haxe: Update to stable version 3.00.

So, finally, Haxe 3 is stable :-)

An overview of the new features can be found here:

http://haxe.org/manual/haxe3/features



This version now has a new build target "tools", so let's use it.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>