first working version using ByteArray.

Attention: unit tests don't run through since I had to change the endianness of the byte array.
removed mistakenly added trace-calls
fixed wrong endian-ness of color
fixed typo
copying last 3 elements of vertex in one single call
DisplayObjectContainer: return from setChildIndex() immediately if the index is the same to avoid calling splice() for no reason
Merge pull request #353 from joshtynjala/setchildindex

DisplayObjectContainer: return from setChildIndex() if index is the same
now recognizing utf-16 XML and JSON files
Merge branch 'master' of github.com:PrimaryFeather/Starling-Framework
removed 'isNaN' call to avoid memory allocations (closes #355)
now using RectangleTexture for 'Texture.empty()', as well (closes #354)

Attention: arguments of 'Texture.empty()' have changed!
updated path to my local AIR sdk
minor documentation addition
fixed background loading in demo and scaffold
moved 'backBufferWidth/height' from RenderSupport to Starling instance

This makes it easier to use custom RenderSupport objects.
added method to make screenshot of the stage, saved into BitmapData object
enhanced custom error class descriptions
added some more sanity checks
removed filter margin for full-screen effects (closes #351)
enhanced margin calculation to avoid hard edges