Fixed #911 -- Made template system scoped to the parser instead of the...

Fixed #911 -- Made template system scoped to the parser instead of the template module. Also changed the way tags/filters are registered and added support for multiple arguments to {% load %} tag. Thanks, rjwittams. This is a backwards-incompatible change for people who've created custom template tags or filters. See http://code.djangoproject.com/wiki/BackwardsIncompatibleChanges for upgrade instructions.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@1443 bcc190cf-cafb-0310-a4f2-bffc1f526a37