Now using Milkdrop's DX9 coordinate system for all vertex positions and have the vertex shader take care of transforming these into the OpenGL screen space. Makes calculations easier.
Also continued implementing per-pixel mesh and shader stuff.
Requires a general rewrite of the Milkdrop preset code. Previous implementation was tightly integrated into the code parser, so reusing this code wasn't possible. Additional refactoring was done, finished converting custom wave/shape implementations to use the new expression parser code.
