[Swf9] made pos argument of flash.Vector.slice optional (fixed issue #1745)

git-svn-id: http://haxe.googlecode.com/svn/trunk@6489 f16182fa-f095-11de-8f43-4547254af6c6
renamed FastCell to GenericCell (fixed issue #1747)

git-svn-id: http://haxe.googlecode.com/svn/trunk@6490 f16182fa-f095-11de-8f43-4547254af6c6