Platform : This commit will allow failsafe core context creation on Mac OS X.
Platform : This commit will allow failsafe core context creation on Mac OS X.

Before this commit the default context creation in tryCreateContext
would create the OpenGL 2.1 context.After this commit by default,
the OpenGL 3.2 context is created by default, if this fails
tryCreateContext will fall back to creating a OpenGL 2.1 context.

MiUishadow/magnum,ashimidashajia/magnum,MiUishadow/magnum,ashimidashajia/magnum,DerThorsten/magnum,DerThorsten/magnum,MiUishadow/magnum,DerThorsten/magnum,DerThorsten/magnum,MiUishadow/magnum,ashimidashajia/magnum,ashimidashajia/magnum,ashimidashajia/magnum,MiUishadow/magnum,MiUishadow/magnum,DerThorsten/magnum