apply type parameters before checking type equality for abstract casts (fixed issue #1770)

git-svn-id: http://haxe.googlecode.com/svn/trunk@6561 f16182fa-f095-11de-8f43-4547254af6c6
apply context type parameters only if there is a with type (for GADT handling) (fixed issue #1772)

git-svn-id: http://haxe.googlecode.com/svn/trunk@6562 f16182fa-f095-11de-8f43-4547254af6c6