New features:
- all : added -D deprecation-warnings
- all : allowed \u escape sequences in strings
- cs : implemented haxe.CallStack
Bugfixes:
- all : fixed wrong handling of "" and null in haxe.io.Path.join
- all : fixed invalid cast-to-self generation on some abstracts
- all : removed @:to Dynamic from UInt to avoid issues in the Map selection algorithm
- all : fixed various issues with UInt
- all : fixed position setter in haxe.io.BytesInput
- all : fixed various issues with member/static extension macros
- flash : fixed invalid override involving single-constraint type parameters
- flash8 : fixed various bugs
- js : fixed a problem with Std.string(null) being optimized incorrectly
- js : fixed custom generators
- cpp : dealt with string literals that are too long for MSVC
- cs : fixed various issues with -net-lib