Template filters now pass numerical arguments through as numbers.

This was the (undocumented) behaviour prior to r10118 and now it's back
again. It's neither hard nor harmful to maintain compatibility with the
old ways.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10169 bcc190cf-cafb-0310-a4f2-bffc1f526a37