Overhaul of sprite batching - split into Engine3D and Engine2D versions with common code refactored to be common & improved general handling of batching & incorporated particle renderer into sprite batching rather than it running it's own old deprecated system. Improvements to COLLADA parsing/model - added support for <asset> nodes and built in rotation of meshes to account for the defined up_axis (no built in scaling for <unit> so far & improved scene graph model so that everything is a node which is a much cleaner impl. Renamed MeshGroup and associated classes to RenderObjGroup which is more clear since (long time ago) support for non-meshes was added. Matrices - added transpose function which was oddly missing & fixed left/right vector confusion & added Matrix3 and Matrix2 classes representing 3x3 and 2x2 matrices respectively. TextureUtils - Fixed minor bug in sheet indexing to do with odd and even indexes & improved general ambiguity in loading. Minor improvements to JavaCodeGen. Added in default implementations for DesktopGUtils services since mostly services are unnecessary anyway.