[cpp] Cat up extra parameters

git-svn-id: http://haxe.googlecode.com/svn/trunk@6576 f16182fa-f095-11de-8f43-4547254af6c6
allow empty classes as abstract implementation

git-svn-id: http://haxe.googlecode.com/svn/trunk@6577 f16182fa-f095-11de-8f43-4547254af6c6