Common:
- [x] Make it compile
- [x] Window implementation
- [x] Fix shader compilation
- [x] Downscale textures
- [ ] Simplify geometry
- [x] Touch controls
- [x] Keyboard controls
- [ ] Audio?
- [x] Menu
- [x] Config
- [x] Merge S60v3 and ^3 branches
- [ ] Move map to top left corner
- [ ] Do something with sprites, they're still taking too much frame time

GLES 2.0 specific:
- [x] Optimize to always run 10+ fps
- [x] Fix skinning shader (cutscene heads require it)
- [ ] Optimize to always run 20+ fps
- [ ] Use etc1 compression
- [ ] Fix face animations in optimized builds

GLES 1.1 specific:
- [x] Backport to STLport v4
- [x] GLES 1.1 engine
- [ ] Keyboard mappings for both QWERTY/12-keys
- [ ] Use pvrtc compression

Issues:
- [x] Fix crash in Texture::destroy on exit
- [x] Save menu is too slow
- [x] HUD disappearing on GLES 2.0 (mostly fixed, was caused by OOM)
- [x] Crash when picking up a bat