Fix bug 900287: Add filter by locale and template name to admin.
Fix bug 900287: Add filter by locale and template name to admin.

Admins have been having trouble filtering by locale, as they mistakenly
thought the old set of Client Match Rules would let them filter by 
locale. We're fixing this by adding the ability to filter by the real
locale field, and also adding the ability to filter by template so that
they can filter out old imported snippets during their searches.
glogiotatidis/snippets-service,mozmar/snippets-service,mozilla/snippets-service,Osmose/snippets-service,schalkneethling/snippets-service,mozilla/snippets-service,mozmar/snippets-service,akatsoulas/snippets-service,akatsoulas/snippets-service,mozmar/snippets-service,schalkneethling/snippets-service,mozilla/snippets-service,bensternthal/snippets-service,glogiotatidis/snippets-service,bensternthal/snippets-service,schalkneethling/snippets-service,glogiotatidis/snippets-service,akatsoulas/snippets-service,Osmose/snippets-service,glogiotatidis/snippets-service,mozilla/snippets-service,Osmose/snippets-service,bensternthal/snippets-service,mozmar/snippets-service,akatsoulas/snippets-service,Osmose/snippets-service,bensternthal/snippets-service,schalkneethling/snippets-service