Issue #1999328 by DmitryDrozdik, annikaC, jeroen12345, andypost: Remove comment_save() and comment_delete()/comment_delete_multiple() in favor of $comment->save()/$comment->delete().

Issue #1620010 by dawehner, ParisLiakos, plach, jibran: Move LANGUAGE constants to the Language class.

Issue #1253820 by yched, zserno, tim.plunkett, xjm, effulgentsia, plach: Fixed It's impossible to submit no value for a field that has a default value.

Issue #1812034 by xjm: Only use standard profile where necessary in comment.module tests (10% bot speed-up).