doc: add a page aggregating OpenGL-ES- and WebGL-specific features.

Thanks Google, for your careless fuckall way of creating private ANGLE
extensions that then immediately get exposed to Chrome and Chrome only.
Way to go!!

doc/Doxyfile

@@ -297,6 +297,7 @@ ALIASES                = \
     "requires_gles=@xrefitem requires-gles \"Requires OpenGL ES or desktop OpenGL\" \"Functionality requiring OpenGL ES or desktop OpenGL\"" \
     "requires_webgl20=@xrefitem requires-webgl20 \"Requires WebGL 2.0\" \"Functionality requiring WebGL 2.0\"" \
     "requires_webgl_extension=@xrefitem requires-webgl-extension \"Requires WebGL extension\" \"Functionality requiring specific WebGL extension\"" \
+    "requires_gles_only=@xrefitem requires-gles-only \"OpenGL ES-only and WebGL-only\" \"OpenGL ES-only and WebGL-only functionality\"" \
     "requires_gles20_only=@xrefitem requires-gles20-only \"OpenGL ES 2.0-only and WebGL 1.0-only\" \"OpenGL ES 2.0-only and WebGL 1.0-only functionality\"" \
     "requires_webgl_only=@xrefitem requires-webgl-only \"WebGL-only\" \"WebGL-only functionality\"" \
     "webgl_extension{2}=<a href=\"https://www.khronos.org/registry/webgl/extensions/\1_\2/\">\1_\2</a>" \

doc/Doxyfile-mcss

@@ -54,6 +54,7 @@ ALIASES                = \
     "requires_gles=@xrefitem requires-gles \"Requires OpenGL ES or desktop OpenGL\" \"Functionality requiring OpenGL ES or desktop OpenGL\"" \
     "requires_webgl20=@xrefitem requires-webgl20 \"Requires WebGL 2.0\" \"Functionality requiring WebGL 2.0\"" \
     "requires_webgl_extension=@xrefitem requires-webgl-extension \"Requires WebGL extension\" \"Functionality requiring specific WebGL extension\"" \
+    "requires_gles_only=@xrefitem requires-gles-only \"OpenGL ES-only and WebGL-only\" \"OpenGL ES-only and WebGL-only functionality\"" \
     "requires_gles20_only=@xrefitem requires-gles20-only \"OpenGL ES 2.0-only and WebGL 1.0-only\" \"OpenGL ES 2.0-only and WebGL 1.0-only functionality\"" \
     "requires_webgl_only=@xrefitem requires-webgl-only \"WebGL-only\" \"WebGL-only functionality\"" \
     "webgl_extension{2}=@m_class{m-doc-external} <a href=\"https://www.khronos.org/registry/webgl/extensions/\1_\2/\">\1_\2</a>" \

doc/Doxyfile-public

@@ -50,6 +50,7 @@ ALIASES                = \
     "requires_gles=@xrefitem requires-gles \"Requires OpenGL ES or desktop OpenGL\" \"Functionality requiring OpenGL ES or desktop OpenGL\"" \
     "requires_webgl20=@xrefitem requires-webgl20 \"Requires WebGL 2.0\" \"Functionality requiring WebGL 2.0\"" \
     "requires_webgl_extension=@xrefitem requires-webgl-extension \"Requires WebGL extension\" \"Functionality requiring specific WebGL extension\"" \
+    "requires_gles_only=@xrefitem requires-gles-only \"OpenGL ES-only and WebGL-only\" \"OpenGL ES-only and WebGL-only functionality\"" \
     "requires_gles20_only=@xrefitem requires-gles20-only \"OpenGL ES 2.0-only and WebGL 1.0-only\" \"OpenGL ES 2.0-only and WebGL 1.0-only functionality\"" \
     "requires_webgl_only=@xrefitem requires-webgl-only \"WebGL-only\" \"WebGL-only functionality\"" \
     "webgl_extension{2}=@m_class{m-doc-external} <a href=\"https://www.khronos.org/registry/webgl/extensions/\1_\2/\">\1_\2</a>" \

doc/opengl.dox

@@ -81,6 +81,7 @@ is supported on older Intel GPUs even if they are capable of OpenGL 2.1 only).
 -   @subpage requires-gles
 -   @subpage requires-webgl20
 -   @subpage requires-webgl-extension
+-   @subpage requires-gles-only
 -   @subpage requires-gles20-only
 -   @subpage requires-webgl-only
 
@@ -141,7 +142,7 @@ is supported on older Intel GPUs even if they are capable of OpenGL 2.1 only).
 
 The following symbols are not defined when targeting OpenGL ES or WebGL.
 
-@see @ref MAGNUM_TARGET_GLES
+@see @ref MAGNUM_TARGET_GLES, @ref requires-gles-only
 */
 
 /** @page requires-gles30 Functionality requiring OpenGL ES 3.0
@@ -182,13 +183,23 @@ The following symbols are not defined when targeting WebGL.
  * @m_footernavigation
  */
 
+/** @page requires-gles-only OpenGL ES-only and WebGL-only functionality
+@m_footernavigation
+
+The following symbols are not defined when targeting desktop OpenGL.
+
+@see @ref MAGNUM_TARGET_GLES2, @ref requires-gles20-only,
+    @ref requires-webgl-only
+*/
+
 /** @page requires-gles20-only OpenGL ES 2.0-only and WebGL 1.0-only functionality
 @m_footernavigation
 
 The following symbols are not defined when targeting OpenGL ES 3.0, WebGL 2.0
 or desktop OpenGL.
 
-@see @ref MAGNUM_TARGET_GLES2, @ref requires-webgl-only
+@see @ref MAGNUM_TARGET_GLES2, @ref requires-gles-only,
+    @ref requires-webgl-only
 */
 
 /** @page requires-webgl-only WebGL-only functionality
@@ -197,5 +208,6 @@ or desktop OpenGL.
 The following symbols are not defined when targeting OpenGL ES or desktop
 OpenGL.
 
-@see @ref MAGNUM_TARGET_WEBGL, @ref requires-gles20-only
+@see @ref MAGNUM_TARGET_WEBGL, @ref requires-gles-only,
+    @ref requires-gles20-only
 */

doc/portability.dox

@@ -51,8 +51,8 @@ Example usage:
 @snippet MagnumGL.cpp portability-targets
 
 Each feature is marked accordingly if it is not available in some targets. See
-also @ref requires-gl, @ref requires-gles30, @ref requires-gles20-only and
-@ref requires-webgl-only.
+also @ref requires-gl, @ref requires-gles30, @ref requires-gles-only,
+@ref requires-gles20-only and @ref requires-webgl-only.
 
 @section portability-compiler Compiler- and platform-specific code