Changed loaddata to display 'No fixtures found' and 'Loading XXX fixtures'...

Changed loaddata to display 'No fixtures found' and 'Loading XXX fixtures' only if verbosity level is greater than 2. It's not necessary to display those messages all of the time, and they're confusing to new users.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@6883 bcc190cf-cafb-0310-a4f2-bffc1f526a37