Shaders, Background for water

Started on shaders for the crystal.
Started on a background quad for water effect.
Start working on .obj loading.
Merge from chris' changes.
Minor cleanups. Fix alpha of the background so it displays consistently.
Another minor fixup.
If a mouse-down during a dialog results in a mouse-up after, shape_being_drawn might be None when we get the event. Don't die when this happens.
Some fixes to crystal rendering.
Sea is blue.
Merge branch 'master' of github.com:darabos/pyweek-nemesis

Conflicts:
	run_game.py