Added support for ofGLProgrammableRenderer, OpenGL 3.2 and ofFbo publishing

Here's a quick and dirty attempt for using Syphon with OpenGL Core.

Most credit goes to Pat Wilson (ZeroStride), who has a branch of Syphon that worked with ofGLProgrammableRenderer. I've compiled his repo at https://github.com/GameClay/syphon-framework/tree/PSW-OpenGL3 and substituted the included Syphon.framework with his.

Please test if it works for you - and don't forget to double-check that the new and included Syphon.framework is the one you link against and copy to your products'  frameworks folder in your copy files build phase.