Removed APPLE_flush_buffer_range from extension list.

Not mentioned anywhere, doesn't add anything to ARB_map_buffer_range.

doc/opengl-support.dox

@@ -48,14 +48,12 @@ following:
 @subsection opengl-support-30 OpenGL 3.0
 
 @todo Replace @extension{APPLE,vertex_array_object} with ARB version (we use only ARB functions without APPLE fallback)
-@todo @extension{APPLE,flush_buffer_range} doesn't add anything to @extension{ARB,map_buffer_range} (remove it and leave only ARB one)
 @todo @extension{EXT,texture_array} overlaps with @extension{ARB,framebuffer_object}
 @todo Add @extension{ARB,depth_buffer_float} and implement the missing @fn_gl{DepthRange} function, but keep (and implement) @extension{NV,depth_buffer_float} for non-linear depth buffer
 @todo @extension{ARB,half_float_pixel}, @extension{ARB,half_float_vertex}?
 
 %Extension                                   | Status
 -------------------------------------------- | ------
-@extension{APPLE,flush_buffer_range}         | done (GL 3.0 subset)
 @extension{APPLE,vertex_array_object}        | done (GL 3.0 subset)
 @extension{ARB,map_buffer_range}             | done
 @extension{ARB,color_buffer_float}           | |

src/Magnum/Context.cpp

@@ -72,7 +72,6 @@ const std::vector<Extension>& Extension::extensions(Version version) {
         _extension(GL,EXT,debug_marker),
         _extension(GL,GREMEDY,string_marker)};
     static const std::vector<Extension> extensions300{
-        _extension(GL,APPLE,flush_buffer_range),
         _extension(GL,APPLE,vertex_array_object),
         _extension(GL,ARB,map_buffer_range),
         _extension(GL,ARB,color_buffer_float),

src/Magnum/Extensions.h

@@ -74,7 +74,6 @@ namespace GL {
         _extension(GL,AMD,vertex_shader_layer,          GL210,  None) // #417
         _extension(GL,AMD,shader_trinary_minmax,        GL210,  None) // #428
     } namespace APPLE {
-        _extension(GL,APPLE,flush_buffer_range,         GL210, GL300) // #321
         _extension(GL,APPLE,vertex_array_object,        GL210, GL300) // #273
     } namespace ARB {
         _extension(GL,ARB,texture_rectangle,            GL210, GL310) // #38