Massive GL3.3 changes - Ready for testing

These are some massive changes to the GL3.3 graphics system (it also touches other places). In short:
1) Better errors for GLSL together with more caching.
2) Surfaces now have optional depth buffers. This allows using them for rendering 3D scenes on them, which is basis of many graphics fx, like reflections, refractions and post-processing.
3) Added functions to use attributes and matrices, both of which are now cached.
4) Added proper GL3.3. debug context together with error function. This means when you run GL3.3 in debug mode, then it will error (segfault) whenever you use a deprecated function or wrong enum. Then it prints the function to console. I will probably add proper error window later. This is very useful when we are trying to get rid of deprecated functions or when we have a hard to find bug (like wrong enum in a function argument). By doing this I removed many functions, fixed many others. In the end it fixed AMD problems we were having and I removed the "hack" that was used previously. That also means that normally ENIGMA users shouldn't see those errors (as they wont use GL directly), and so this could be an additional debug mode (graphics debug mode), so that we don't drop frames without reason (this GL debug mode really does drop FPS).
5) Fixed view_angle in GL1 and GL3.
6) Started on the GPU profiler. It would basically keep track of vertices, triangles, texture swaps, draw calls and so on per frame. This is of course done in debug mode for now. Many changes to come in this regard, as well as a forum post to explain this in more detail.
7) Updated GLEW. This wasn't necessarily needed, but it's always good to have newer stuff. The reason I did it though is because I needed to get rid of glGetString(GL_EXTENSIONS) which was in glew.c. This function with this argument is deprecated, and so it always crashed at startup in debug context. The newest versions (1.10) still doesn't remove that function call, but I found many code snippets on the net that replace it.

I would like if some other people tested it. I have tried it on AMD laptop and NVIDIA PC. Will do some additional tests later.