Core (Docs): Update links and C version requirement in readme files

libvisual/README

@@ -36,9 +36,9 @@ The images in tests/images are licensed under Creative Commons
 (CC). See tests/images/license.txt for details.
 
 Full license texts:
-* LGPL v2.1: http://www.gnu.org/licenses/lgpl-2.1.html
-* GPL v2.0 : http://www.gnu.org/licenses/gpl-2.0.html
-* CC       : http://creativecommons.org/licenses/
+* LGPL v2.1: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
+* GPL v2.0 : https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+* CC       : https://creativecommons.org/licenses/
 
 Development
 -----------
@@ -52,7 +52,7 @@ Software Requirements
 
 C/C++20 compiler
 
-    Libvisual uses several C99 and C++20 features for its modern API
+    Libvisual uses several C11 and C++20 features for its modern API
     design and implementation, and as such, requires an up-to-date
     C/C++ compiler to build. Compilers tested and known to work are
     GCC 11+ and Clang 14+.
@@ -62,14 +62,14 @@ Libraries
     The core library is fairly self-contained and requires almost very
     little dependencies other than the standard C99 and C++11 libraries.
 
-    The Oil Runtime Compiler (http://code.entropywave.com/orc) (ORC)
-    is required for generating a portion of Libvisual's SIMD routines.
+    The Oil Runtime Compiler (https://gstreamer.freedesktop.org/projects/orc.html)
+    (ORC) is required for generating a portion of Libvisual's SIMD routines.
 
     GNU Gettext is optionally required (see note) for
     internationalisation.
 
     The bundled examples, benchmarks and test programs mostly require
-    SDL 1.2 (http://libsdl.org).
+    SDL 1.2 (https://www.libsdl.org).
 
     ** Note: Gettext is integrated into glibc on Linux.
 
@@ -78,7 +78,7 @@ Compiling and installing
 
 Configuration
 
-    Building Libvisual requires CMake 3.20 (http://www.cmake.org) or
+    Building Libvisual requires CMake 3.20 (https://www.cmake.org) or
     above. The command to configure the build is:
 
         cmake .

libvisual/README.md

@@ -22,11 +22,11 @@ necessary for display in any Libvisual-using application.
 
 The Libvisual library that is in libvisual/ is licensed under the
 Lesser GNU General Public License (LGPL) v2.1
-([full text](http://www.gnu.org/licenses/lgpl-2.1.html)).
+([full text](https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html)).
 
 The example applications in examples/ are licensed under the General
 GNU Public License (GPL) v2
-([full text](http://www.gnu.org/licenses/gpl-2.0.html)).
+([full text](https://www.gnu.org/licenses/old-licenses/gpl-2.0.html)).
 
 The tools in tools/ are licensed under the GPLv2.
 
@@ -40,7 +40,7 @@ very useful information regarding our coding policies and such.
 
 #### C/C++ compiler
 
-Libvisual uses several C99 and C++20 features for its modern API
+Libvisual uses several C11 and C++20 features for its modern API
 design and implementation, and as such, requires an up-to-date C/C++
 compiler to build. Compilers tested and known to work are GCC 11+ and
 Clang 14+.
@@ -50,22 +50,22 @@ Clang 14+.
 The core library is fairly self-contained and requires almost very
 little dependencies other than the standard C99 and C++20 libraries.
 
-The [Oil Runtime Compiler](http://code.entropywave.com/orc) (ORC) is
+The [Oil Runtime Compiler](https://gstreamer.freedesktop.org/projects/orc.html) (ORC) is
 required for generating a portion of Libvisual's SIMD routines.
 
 GNU Gettext is optionally required (see note) for
 internationalisation.
 
 The bundled examples, benchmarks and test programs mostly require
-[SDL 1.2](http://libsdl.org).
+[SDL 1.2](https://www.libsdl.org).
 
 Note: Gettext is integrated into glibc on Linux.
 
 ### Compiling and Installing
 
 #### Configuration
 
-Building Libvisual requires [CMake 3.20](http://www.cmake.org) or
+Building Libvisual requires [CMake 3.20](https://www.cmake.org) or
 above. The command to configure the build is:
 
     cmake .