added new 'execute' utility function and using it in RenderTexture
simplified and optimized 'execute' function
... and a little more
added protected property allowing access to objects vector (closes #515)
Removing dead code

Small change to remove dead code that triggers warnings in some editors/code analyzers. No change of functionality.
Merge pull request #521 from zeh/patch-1

Removing dead code
disabled strict mode for asdoc compilation (closes #518)
added 'muted' property to movie clip (closes #519)
now optionally keeping atlas and font XMLs in AssetManager so that they can be accessed later (refs #445)
Merge branch 'master' of https://github.com/PrimaryFeather/Starling-Framework

Conflicts:
	starling/src/starling/utils/AssetManager.as
Merge branch 'master' of https://github.com/peerobo/myStarling