Persist friend and me objects in ApplicationController.

The idea is to do the facebook pull and create the friends list only
once; right now am doing it in the very first search but it would be
nice to start it the second the user signs in. The me and friend data
is then persisted as global objects in the application controller,
this so that they aren't pulled every time there is a search -- the
search now operates on a subset of them. Still pretty ugly...

Also want to a) only geocode any given friend once (for the life of
the global friend list), and b) only geocide any location, amongst all
friends with that location, once. As of right now, each search
constructs, from the global friends list, a new set of geocoded
friends meeting its criteria, so number of friends and the friend's
location is within 50 (arbitrary) miles of the search region.