Download and cache all factsheet info upon load

[EddieCurtis]

Instead of caching each individual search, we can download all of the factsheet info in one go (maybe in an AsyncTask on app load) and cache that instead. The only issue this would cause is we then need to find a way to parse the aliases ourselves, but that shouldn't be too hard. I guess it would all be loaded into a Map where different keys point to the same object.

Full factsheet download: http://tripbot.tripsit.me/api/tripsit/getAllDrugs