detect recursive implicit casts (fixed issue #1572)

git-svn-id: http://haxe.googlecode.com/svn/trunk@6347 f16182fa-f095-11de-8f43-4547254af6c6
check casts for individual case expressions (fixed issue #1574)

git-svn-id: http://haxe.googlecode.com/svn/trunk@6348 f16182fa-f095-11de-8f43-4547254af6c6
obsolete

git-svn-id: http://haxe.googlecode.com/svn/trunk@6349 f16182fa-f095-11de-8f43-4547254af6c6