NiallsAVLib ToDo
----------------
- Implement a GLESDrawer.
	- Implement:
		- drawSubImage()
		- drawTiledImage()
		- drawText() (both)
		- drawConnectedLine()
		- fillGradient()
	- Currently no proper implementation of the second texture.
		- Take the same approach as with avlTextureExists.
	- Implement a text renderer which renders everything to a single VBO
	  (will need to handle situations when glyphs are in an additional atlas).
	- Make sure none of the other methods use non-ES functions.
	- Runtime check: are Vertex Array Objects available? (& a fallback?)
	- Make various default shader uniform locations specific to each shader.
- Fix shaders not loading on OSX.
- Can we make UTF8File's read/write methods all rely on wstringToChar() and
  charToWstring()?
- Come up with a distinctive abstract loading screen.
- Fix GameState::keyUp()'s keyPressed member (& keyDown()?).
- Port to SDL1.3.

- NOTE: Vertex Array Objects are available on all iOS devices running iOS 4.0 or
  higher.

- Profiling: The two biggest slowdowns seem to be GLMatrix::multiplyWithTemp()
  and wstring::compare().

- Should I move away from TwoFloats and ThreeFloats to something more
  generalisable?
- Try and fix delay on quit under Linux (related to audio device; seems to be
  out of my hands?).
- Test PortAudio ASIO driver.
- Add option to call a callback when StreamingSound reaches a particular point
  in its sound file.
- Make it possible to set a default font - if not set, ensure we have a basic
  font set to be used as the default.
- Add a way of passing system fonts to the app via the AVLibResourceGenerator?
- Add option to load font from memory.
- Add option to load sounds from memory.
- Develop generic options screen including resolution, fullscreen and v-sync
  options.
- Should be able to change resolutions without requiring a full restart.
- Ports:
	- SDL 1.2 (for Linux support more than anything).
	- SDL 1.3 (everything else).
	- Cocoa (iOS)?
- Audio ports:
	- SDL 1.2.
	- SDL 1.3.
	- PortAudio.
	- Cocoa/iOS?
- Make a high scores abstract base class.
- HighScores ports:
	- GameCenter.
	- ?
