anidb: rename misc.go to globals.go
anidb: Make (*AniDB).User() try harder to return a user

Will block for at least 2 seconds if the user ID is not cached. Any UDP
API access will cache the user ID.
anidb: Also cache the EID-AID relationship when caching FILE results
anidb: Add AnimeCount() call
anidb: allow (*udpWrap).SendRecv to be called with nil parameters
anidb: Implement MYLISTSTATS