Overgrowth Alpha 204

- Added tool to attach environment objects to character skeletons
- Added NVTX labels for GPU profiling
- Converted most immediate-mode drawing to use vertex arrays or VBOs
- Improved VBO and line-width state shadowing
- Reduced per-frame memory allocations
- Static physics AABBs are only updated as needed
- Added angelscript benchmarking functions
- Fixed performance issue with ASGetObjectIDArray
- Fixed vec3 normalization issue which could cause random crashes