Cleaned up constants and variable names in com.mojang.minecraft.render.Renderer
Renamed MinecraftApplet$1 to MinecraftCanvas
Got rid of a 'this' leak in ParticleManager constructor. Level.particleEngine field is set in Minecraft.setLevel anyway, so this was never needed.
Merge pull request #251 from fragmer/master

Minor cleanup in Renderer, ParticleManager, and MinecraftApplet