Fixed a few problems with variable resolving inside of blocktrans tags. A...

Fixed a few problems with variable resolving inside of blocktrans tags. A couple of these were exposed by the auto-escaping changes, but I suspect the other one has been hiding in plain sight for a while.

Fixed #5952, #5953


git-svn-id: http://code.djangoproject.com/svn/django/trunk@6682 bcc190cf-cafb-0310-a4f2-bffc1f526a37