Feature programmable gl

Hey Lukasz,

I've extended your branch by adding GL3.2+ support, whilst keeping compatibility with GLES2, GL and GLES. 

I've also renamed GLES2Renderer to ofProgrammableGLRenderer following the last oF IRC meetup, so that we have a unified programmable renderer which ties in both programmable pipelines.

I've tested my commits on GL, GLES2 and GL3.2(Core Profile) on Mac (10.8, ATI) Linux (arch linux, nvidia v. 318) and iPad (iOS 6.1). I consider the new OpenGL 3.2+ renderer code pretty much alpha and ready for further testing...

If you pull this branch from my github (https://github.com/tgfrerer/ofxGL3Renderer/tree/testcase_new_of_renderer) and drop it into your addons directory, you'll get a testcase project for Linux(makefile / sublime text based) / and OS X (XCode Projectfile based) using GLFW.

I'll be around on IRC (freenode), via mail and on github if you'd like to know more.

Cheers
#

Tim