OpenGL 4 core profile support

[febret]

• Add a openGLCoreProfile flag to DisplayConfig, set to false by default. When true, OpenGL is initialized in compatibility profile
• Initially disable certain functionality that will take longer to translate to core GL 4.
• modules can mark themselves as forward compatible if they only use functionality available in core profiles.
  Add the following methods to EngineModule

requestOpenGLProfile(OpenGLProfile)
OpenGLProfile:
{
   Core,
   Compatibility,
   Unspecified
};

This method can be used within an engine module ctor or initialization to test for module compatibility. After initialization, the module will test requested profile against
what the display system is running.

• Core: if openGLCoreProfile = true ok, otherwise print a warning (on OSX only?) that core features will not be available.
• Compatibility: if openGLCoreProfile = true print an error and shutdown the application, otherwise ok
• Unspecified: if openGLCoreProfile = true print a verbose mode log message (not warning) that a potentially incompatible module is running, otherwise ok