added Type.s_expr_pretty and improved exhaustion error messages (fixed issue #1352)

git-svn-id: http://haxe.googlecode.com/svn/trunk@5804 f16182fa-f095-11de-8f43-4547254af6c6
removed obsolete s_const in matcher.ml

git-svn-id: http://haxe.googlecode.com/svn/trunk@5805 f16182fa-f095-11de-8f43-4547254af6c6
Merge branch 'haxe/master'