Dmcbride/embassy

Code to fix issue #215.

Note that there are also some extra functions in here (Lacuna->db) which make running quick tests at the command line a bit easier.  Not sure if you want to keep those or not.  Also a change for the SS's: empire status shows the primary embassy ID so that API users don't need to hunt through every body looking for an embassy to use for voting.  This may also help Vasari with the new UI.