- splits kwinglutils into multiple files
- removes functionality meant for legacy OpenGL from GLVertexBuffer
- removes streaming buffer etc from GLVertexBuffer in favor of just calling
glBufferData. This greatly simplifies the code and most likely has 0 impact on performance
- simplifies the index buffer implementation by always generating the index array at runtime and also always using
- enables error message printing even if not requested with the env var. While it might make sense to suppress debug messages without it, we always want to know when there's errors
For the details look at the commits themselves.