Version 0.5: Now jmini3d works pretty well with 2d :P
- new package for materials
- now HUD uses standard x-y screen coordinates
- now the scene has a onViewPortChanged method to notice viewport changes (also called in the viewport initialization). Must be called by the SceneController
- SpriteGeometry and MaterialGeometry for HUD elements
- Updated the demos to show HUD elements (and how to reposition them after viewport changes)