Enabled partial match search

Now searching for even partial tags within favourites will bring up all
gifs that match the partial, for example 'deal' will bring up 'deal with
it', 'what's the deal', and 'deal or not'. This may not be ideal in all
circumstances, but for the most part it should increase the usability of
the favourites search and bring up gifs that wouldn't have been brought
up without typing the exact search term i.e. cry will also bring up
crying.