Further work to #43.
It should be noted that we have discovered a significant flaw in the
initialisation of field objects, in that all new users (users who have
previously not been recorded by depressionbot in the currently active
instance) share the same data arrays causing hours of confusion.

This commit adds API functionality for fetching users on a given
server-channel combination, leaderboarding various metrics but does
however link a majority of commands to the new API interfaces.

~active has been disabled once again for the time being as I still
decide the best method to allow the API to support this data structure.