Added support for EXT_framebuffer_sRGB.

Added sRGB extensions to standards conformance page.

docs/compat.dox

@@ -117,6 +117,11 @@ whether a context is flushed when it is released (made non-current).  Where this
 extension is unavailable, the `GLFW_CONTEXT_RELEASE_BEHAVIOR` hint will have no
 effect and the context will always be flushed when released.
 
+GLFW uses the `GLX_ARB_framebuffer_sRGB` and `GLX_EXT_framebuffer_sRGB`
+extensions to provide support for sRGB framebuffers.  Where both of these
+extensions are unavailable, the `GLFW_SRGB_CAPABLE` hint will have no effect.
+
+
 @section compat_wgl WGL extensions
 
 The WGL API is used to create OpenGL contexts on Microsoft Windows and other
@@ -154,6 +159,11 @@ whether a context is flushed when it is released (made non-current).  Where this
 extension is unavailable, the `GLFW_CONTEXT_RELEASE_BEHAVIOR` hint will have no
 effect and the context will always be flushed when released.
 
+GLFW uses the `WGL_ARB_framebuffer_sRGB` and `WGL_EXT_framebuffer_sRGB`
+extensions to provide support for sRGB framebuffers.  Where both of these
+extension are unavailable, the `GLFW_SRGB_CAPABLE` hint will have no effect.
+
+
 @section compat_osx OpenGL 3.2 and later on OS X
 
 Support for OpenGL 3.2 and above was introduced with OS X 10.7 and even then

docs/window.dox

@@ -206,6 +206,8 @@ Zero disables multisampling.  `GLFW_DONT_CARE` means the application has no
 preference.
 
 `GLFW_SRGB_CAPABLE` specifies whether the framebuffer should be sRGB capable.
+If supported, the created context will provide `GL_ARB_framebuffer_sRGB` or
+`GL_EXT_framebuffer_sRGB`.
 
 `GLFW_DOUBLEBUFFER` specifies whether the framebuffer should be double buffered.
 You nearly always want to use double buffering.  This is a hard constraint.