Update the doxyfile

- use SVG figures (more appropriate if we're going to commit doxygen output to GitHub)
- use MathJax to avoid the LaTeX dependency and lots of figures it would generate
- remove graphs illustrating include dependencies (to save space)

doc/browser/doxyfile

@@ -765,6 +765,8 @@ GENERATE_HTML          = YES
 
 HTML_OUTPUT            = html/
 
+USE_MATHJAX            = YES
+
 # The HTML_FILE_EXTENSION tag can be used to specify the file extension for
 # each generated HTML page (for example: .htm,.php,.asp). If it is left blank
 # doxygen will generate files with .html extension.
@@ -1142,11 +1144,6 @@ ALLEXTERNALS           = NO
 
 EXTERNAL_GROUPS        = YES
 
-# The PERL_PATH should be the absolute path and name of the perl script
-# interpreter (i.e. the result of `which perl').
-
-PERL_PATH              = /usr/bin/perl
-
 #---------------------------------------------------------------------------
 # Configuration options related to the dot tool
 #---------------------------------------------------------------------------
@@ -1160,15 +1157,6 @@ PERL_PATH              = /usr/bin/perl
 
 CLASS_DIAGRAMS         = YES
 
-# You can define message sequence charts within doxygen comments using the \msc
-# command. Doxygen will then run the mscgen tool (see
-# http://www.mcternan.me.uk/mscgen/) to produce the chart and insert it in the
-# documentation. The MSCGEN_PATH tag allows you to specify the directory where
-# the mscgen tool resides. If left empty the tool is assumed to be found in the
-# default search path.
-
-MSCGEN_PATH            =
-
 # If set to YES, the inheritance and collaboration graphs will hide
 # inheritance and usage relations if the target is undocumented
 # or is not a class.
@@ -1240,7 +1228,7 @@ TEMPLATE_RELATIONS     = YES
 # file showing the direct and indirect include dependencies of the file with
 # other documented files.
 
-INCLUDE_GRAPH          = YES
+INCLUDE_GRAPH          = NO
 
 # If the ENABLE_PREPROCESSING, SEARCH_INCLUDES, INCLUDED_BY_GRAPH, and
 # HAVE_DOT tags are set to YES then doxygen will generate a graph for each
@@ -1281,7 +1269,7 @@ DIRECTORY_GRAPH        = NO
 # generated by dot. Possible values are png, jpg, or gif
 # If left blank png will be used.
 
-DOT_IMAGE_FORMAT       = png
+DOT_IMAGE_FORMAT       = svg
 
 # The tag DOT_PATH can be used to specify the path where the dot tool can be
 # found. If left blank, it is assumed the dot tool can be found in the path.