Gl3.3 real clean up

Check this topic for more (and the same) info: http://enigma-dev.org/forums/index.php?topic=2272.0

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) Adds a global VAO, which is necessary for GL3.3 core. Making one VAO per mesh might be better, but I had some problems with rendering when I tried that. Worth investigating later.
7) Fixes GL1 models not updating. This is because GL lists are now used for additional batching, but they were not reset when model_clear() was called.
8) The GL1 GL list was never destroyed, thus creating a memory leak problem. Fixed that by destroying the list in mesh destructor. The list is also created once doing the mesh constructor.
9) Fixes surfaces, which were broken in the recent viewport code changes.
10) 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.
11) 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.
12) The color choice is more consistent with GM in GL3. It's hard to explain, but basically the bound color (draw_set_color) will be the default one and it won't blend when using vertex_color. This is basically the fix for the purple floor in Minecraft example. In GL1 the floor was purple, in GL3 it was white. Now in GL3 it is also purple.
13) Fixed shadows in Project Mario (can't remember what did it though).
14) Added alpha test functions for GL3.3. This can also improve performance.
15) Added draw_sprite_padded() which is useful for drawing menus, buttons and other things like that. Will be instrumental in GUI extension I'm working on.

There were many other changes as well, but I have forgotten most of it, as this was originally a mid-august merge.

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.

Also there are performance improvements for GL3 stemming from these changes. Like project mario is now 1620FPS (vs 1430FPS in master).

I recommend testing on:
1) Project Mario - http://enigma-dev.org/forums/index.php?topic=1161.0 (GL1 and GL3).
2) Minecraft example - http://enigma-dev.org/edc/games.php?game=65 (GL1 and GL3).
3) Simple shader example - https://www.dropbox.com/s/6fx3r0bg5puyo28/shader_example.egm (GL3).
I will fix up the water example and post a link as well.

Check this topic for more info: http://enigma-dev.org/forums/index.php?topic=2272.0