Documentation internet addresses

Running a link checker revealed a number of not existing / redirected addresses, these have been corrected.

doc/changelog.doc

@@ -2182,7 +2182,7 @@ make sure you add the following:
 <h3>New features</h3>
 <ul>
 <li>   Added support for 
-       <a href="http://daringfireball.net/projects/markdown/">Markdown</a>
+       <a href="https://daringfireball.net/projects/markdown/">Markdown</a>
        formatting.
        This is enabled by default, but can be disabled by 
        setting MARKDOWN_SUPPORT to NO. When enabled the following is 

doc/docblocks.doc

@@ -632,7 +632,7 @@ and is ideal for a short description.
 For longer descriptions you often will find the 
 need for some more structure, like a block of verbatim text, a list, or a 
 simple table. For this doxygen supports the 
-<a href="http://daringfireball.net/projects/markdown/syntax">Markdown</a> 
+<a href="https://daringfireball.net/projects/markdown/syntax">Markdown</a> 
 syntax, including parts of the
 <a href="https://michelf.ca/projects/php-markdown/extra/">Markdown Extra</a>
 extension. 
@@ -648,8 +648,9 @@ forms of additional markup on top of Markdown formatting.
 
 1. <a href="https://en.wikipedia.org/wiki/Javadoc">Javadoc</a> like markup.
    See \ref commands for a complete overview of all commands supported by doxygen.
-2. <a href="https://en.wikipedia.org/wiki/C_Sharp_(programming_language)#XML_documentation_system">XML</a> markup
-   as specified in the C# standard. See \ref xmlcmds for the XML commands supported by doxygen.
+2. <a href="https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/xmldoc/recommended-tags-for-documentation-comments">XML</a> markup
+   as specified in the <a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/c042926_ISO_IEC_23270_2006(E).zip">C# standard</a>.
+   See \ref xmlcmds for the XML commands supported by doxygen.
 
 If this is still not enough doxygen also supports a \ref htmlcmds "subset" of 
 the <a href="https://en.wikipedia.org/wiki/HTML">HTML</a> markup language.

doc/features.doc

@@ -100,7 +100,7 @@
 Although doxygen can now be used in any project written in a language that is 
 supported by doxygen, initially it was specifically designed to be used for projects 
 that make use of Qt Software's 
-<A HREF="http://qt-project.org/">Qt toolkit</A>. I have tried to 
+<A HREF="https://www.qt.io/developers/">Qt toolkit</A>. I have tried to 
 make doxygen `Qt-compatible'. That is: Doxygen can read the documentation contained in 
 the Qt source code and create a class browser that looks quite similar to the 
 one that is generated by Qt Software. Doxygen understands the C++ extensions 

doc/install.doc

@@ -47,7 +47,7 @@ tools should be installed.
 
 <ul>
 <li>Qt Software's GUI toolkit 
-    <a href="http://qt-project.org/">Qt</A>
+    <a href="https://www.qt.io/developers/">Qt</A>
     \addindex Qt
     version 4.3 or higher (including Qt 5).
     This is needed to build the GUI front-end doxywizard. 
@@ -211,12 +211,12 @@ If you want to produce compressed HTML files (see \ref
 cfg_generate_htmlhelp "GENERATE_HTMLHELP") in the configuration file, then 
 you need the Microsoft HTML help workshop. 
 You can download it from 
-<a href="http://www.microsoft.com/en-us/download/details.aspx?id=21138">Microsoft</a>.
+<a href="https://www.microsoft.com/en-us/download/details.aspx?id=21138">Microsoft</a>.
 
 If you want to produce Qt Compressed Help files (see \ref 
 cfg_qhg_location "QHG_LOCATION") in the configuration file, then 
 you need qhelpgenerator which is part of Qt. 
-You can download Qt from <a href="http://qt-project.org/downloads">Qt Software Downloads</a>.
+You can download Qt from <a href="https://www.qt.io/download">Qt Software Downloads</a>.
 
 In order to generate PDF output or use scientific formulas you will also need to
 install <a href="https://en.wikipedia.org/wiki/LaTeX">LaTeX</a> and 

doc/markdown.doc

@@ -41,7 +41,7 @@ the extensions that doxygen supports.
 Finally section \ref markdown_dox discusses some specifics for doxygen's
 implementation of the Markdown standard.
 
-[markdown]: http://daringfireball.net/projects/markdown/ 
+[markdown]: https://daringfireball.net/projects/markdown/ 
 [mdextra]:  https://michelf.ca/projects/php-markdown/extra/
 [github]:   https://github.github.com/github-flavored-markdown/
 

doc/searching.doc

@@ -126,7 +126,7 @@ has its own advantages and disadvantages:
    options you may want to set. After doxygen has finished you will find
    a Makefile in the HTML output directory. Running "make install" on this
    Makefile will compile and install the doc set.
-   See <a href="https://developer.apple.com/library/mac/#featuredarticles/DoxygenXcode/_index.html">this 
+   See <a href="https://developer.apple.com/library/archive/featuredarticles/DoxygenXcode/_index.html">this 
    article</a> for more info.
 
    Advantage of this method is that it nicely integrates with the Xcode
@@ -139,7 +139,7 @@ has its own advantages and disadvantages:
 <h2>6. Qt Compressed Help</h2> 
    If you develop for or want to install the Qt application framework,
    you will get an application 
-   called <a href="http://qt-project.org/doc/qt-4.8/assistant-manual.html">Qt assistant</a>. 
+   called <a href="http://doc.qt.io/archives/qt-4.8/assistant-manual.html">Qt assistant</a>. 
    This is a help viewer for Qt Compressed Help files (<code>.qch</code>).
 
    To enable this feature set \ref cfg_generate_qhp "GENERATE_QHP" to \c YES.

doc/starting.doc

@@ -263,7 +263,7 @@ capabilities of the man page format, so some information
 \subsection docbook_out DocBook output
 \addindex docbook
 Doxygen can also generate output in the 
-<a href="http://docbook.org/">DocBook</a> format. How to process the
+<a href="https://docbook.org/">DocBook</a> format. How to process the
 DocBook output is beyond the scope of this manual.
 
 \section step3 Step 3: Documenting the sources

src/config.xml

@@ -650,7 +650,7 @@ Go to the <a href="commands.html">next</a> section or return to the
 <![CDATA[
  If the \c MARKDOWN_SUPPORT tag is enabled then doxygen pre-processes all 
  comments according to the Markdown format, which allows for more readable 
- documentation. See http://daringfireball.net/projects/markdown/ for details. 
+ documentation. See https://daringfireball.net/projects/markdown/ for details. 
  The output of markdown processing is further processed by doxygen, so you 
  can mix doxygen, HTML, and XML commands with Markdown formatting. 
  Disable only in case of backward compatibilities issues. 
@@ -2039,15 +2039,15 @@ hr.footer {
 <![CDATA[
  If the \c GENERATE_DOCSET tag is set to \c YES, additional index files
  will be generated that can be used as input for 
- <a href="https://developer.apple.com/tools/xcode/">Apple's Xcode 3
+ <a href="https://developer.apple.com/xcode/">Apple's Xcode 3
  integrated development environment</a>, introduced with OSX 10.5 (Leopard).
  To create a documentation set, doxygen will generate a Makefile in the
  HTML output directory. Running \c make will produce the docset in that
  directory and running <code>make install</code> will install the docset in 
  <code>~/Library/Developer/Shared/Documentation/DocSets</code> 
  so that Xcode will find it at startup. See
- https://developer.apple.com/tools/creatingdocsetswithdoxygen.html for
- more information.
+ https://developer.apple.com/library/archive/featuredarticles/DoxygenXcode/_index.html
+ for more information.
 ]]>
       </docs>
     </option>
@@ -2095,7 +2095,7 @@ The \c DOCSET_PUBLISHER_NAME tag identifies the documentation publisher.
  doxygen generates three additional HTML index files: 
  \c index.hhp, \c index.hhc, and \c index.hhk. The \c index.hhp is a 
  project file that can be read by 
- <a href="http://www.microsoft.com/en-us/download/details.aspx?id=21138">
+ <a href="https://www.microsoft.com/en-us/download/details.aspx?id=21138">
  Microsoft's HTML Help Workshop</a>
  on Windows.
 <br>
@@ -2191,7 +2191,7 @@ The \c DOCSET_PUBLISHER_NAME tag identifies the documentation publisher.
 <![CDATA[
  The \c QHP_NAMESPACE tag specifies the namespace to use when generating
  Qt Help Project output. For more information please see
- <a href="http://doc.qt.io/qt-4.8/qthelpproject.html#namespace">Qt Help Project / Namespace</a>.
+ <a href="http://doc.qt.io/archives/qt-4.8/qthelpproject.html#namespace">Qt Help Project / Namespace</a>.
 ]]>
       </docs>
     </option>
@@ -2200,15 +2200,15 @@ The \c DOCSET_PUBLISHER_NAME tag identifies the documentation publisher.
 <![CDATA[
  The \c QHP_VIRTUAL_FOLDER tag specifies the namespace to use when
  generating Qt Help Project output. For more information please see
- <a href="http://doc.qt.io/qt-4.8/qthelpproject.html#virtual-folders">Qt Help Project / Virtual Folders</a>.
+ <a href="http://doc.qt.io/archives/qt-4.8/qthelpproject.html#virtual-folders">Qt Help Project / Virtual Folders</a>.
 ]]>
       </docs>
     </option>
     <option type='string' id='QHP_CUST_FILTER_NAME' format='string' defval='' depends='GENERATE_QHP'>
       <docs>
 <![CDATA[
   If the \c QHP_CUST_FILTER_NAME tag is set, it specifies the name of a custom filter to add. For more information please see
-  <a href="http://doc.qt.io/qt-4.8/qthelpproject.html#custom-filters">Qt Help Project / Custom Filters</a>.
+  <a href="http://doc.qt.io/archives/qt-4.8/qthelpproject.html#custom-filters">Qt Help Project / Custom Filters</a>.
 ]]>
       </docs>
     </option>
@@ -2217,15 +2217,15 @@ The \c DOCSET_PUBLISHER_NAME tag identifies the documentation publisher.
 <![CDATA[
   The \c QHP_CUST_FILTER_ATTRS tag specifies the list of the attributes of the custom filter to add.
   For more information please see
-  <a href="http://doc.qt.io/qt-4.8/qthelpproject.html#custom-filters">Qt Help Project / Custom Filters</a>.
+  <a href="http://doc.qt.io/archives/qt-4.8/qthelpproject.html#custom-filters">Qt Help Project / Custom Filters</a>.
 ]]>
       </docs>
     </option>
     <option type='string' id='QHP_SECT_FILTER_ATTRS' format='string' defval='' depends='GENERATE_QHP'>
       <docs>
 <![CDATA[
   The \c QHP_SECT_FILTER_ATTRS tag specifies the list of the attributes this project's filter section matches.
-  <a href="http://doc.qt.io/qt-4.8/qthelpproject.html#filter-attributes">Qt Help Project / Filter Attributes</a>.
+  <a href="http://doc.qt.io/archives/qt-4.8/qthelpproject.html#filter-attributes">Qt Help Project / Filter Attributes</a>.
 ]]>
       </docs>
     </option>
@@ -2375,7 +2375,7 @@ The \c DOCSET_PUBLISHER_NAME tag identifies the documentation publisher.
       <value name="NativeMML" desc="(i.e. MathML)"/>
       <value name="SVG"/>
     </option>
-    <option type='string' id='MATHJAX_RELPATH' format='string' defval='https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.2/' depends='USE_MATHJAX'>
+    <option type='string' id='MATHJAX_RELPATH' format='string' defval='https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/' depends='USE_MATHJAX'>
       <docs>
 <![CDATA[
  When MathJax is enabled you need to specify the location relative to the