first basic Sprite3D rendering
introducing a more elegant solution for RenderSupport's 2D/3D duality
added support for rendering of nested 3d containers
added 3d transformation methods to MatrixUtil
implemented hitTest method for Sprite3D
added 2D bounds calculation of Sprite3D; added 3D bounds calculations to 2D objects
added sprite3D demo
added 'is3D' property to display objects, supporting projected bounds for 2D objects within 3D objects
renamed 'Cuboid' to 'Box'
fixed juggler usage in 3d demo
projection matrix 3d now uses x+y offset; fixed filters
camera distance can now be configured via 'stage.z'
fixed copy/paste error in Sprite3D rotation setter
enhanced filter support for 3d objects

Still not working consisently, but a little better, at least. ;)
add missing tests for starling.utils package
fixed projection matrix for regions within the view frustum

Required e.g. for fragment filters, which now work fine for 2D and 3D objects alike.
fixed wrong BitmapData size in 'drawToBitmapData' when using HiDPI display (closes #618)

Starling now contains properties for both "backBufferWidth/Height" and "viewPortWidth/Height";
one returns the actual size in pixels, the other in points. This is necessary because Stage3D is inconsisent with its back buffer dimensions. Some methods (e.g. 'setScissorRectangle') use points, others (e.g. 'backBufferWidth/Height') use pixels.
Merge branch 'feature-utils-tests' of git://github.com/johnikx/Starling-Framework into johnikx-feature-utils-tests
fixed typo
Merge branch 'johnikx-feature-utils-tests'