Add KHR_debug definitions
Load KHR_debug on Linux
Fix import problem
Define GL callback func. Improve GL err macro.
Implement debug callback
Enable all messages
Improve formatting
Stop mipmap allocation for textures
Add GL_ARB_debug_output
Add debug markers and labels
Fix iOS compile
Merge pull request #670 from mapbox/gl-debug

Use GL debug callbacks
update nunicode version to 1.5.1
untabify
More complete uv::thread
Adhere to naming conventions
Texturepool ⇢ TexturePool (fixes #655)
Remove unnecessary cast
add array overloads to make_unique and move it to mbgl::util from std
don't set the window title on every frame

this is a significant performance penalty, at least on OS X, and drops our frame rate below 60fps on even simple scenes. instead of showing the position of the map in the window, we should display it elsewhere