restructed abstract handling in type_field and removed unification (fixed issue #1522)

git-svn-id: http://haxe.googlecode.com/svn/trunk@6310 f16182fa-f095-11de-8f43-4547254af6c6
minor non-breaking renaming

git-svn-id: http://haxe.googlecode.com/svn/trunk@6311 f16182fa-f095-11de-8f43-4547254af6c6
added Map.toString and made sure Std.string is called on the keys of ObjectMap (fixed issue #1540)

git-svn-id: http://haxe.googlecode.com/svn/trunk@6312 f16182fa-f095-11de-8f43-4547254af6c6
detect reification mode from ECheckType(..., Expr) for now

git-svn-id: http://haxe.googlecode.com/svn/trunk@6313 f16182fa-f095-11de-8f43-4547254af6c6