Optional starting balance, purely virtual

Toss some money straight into the DB on account creation, as per the
config. Mostly tested.
Fix NPE originating in FactionAccountHolder

Help id.startsWith("faction-") realize its truthiness.
(Todo: Convert/clean up old Factions DB records.)
Sketchy chest location for attached signs

Locate chests with attached signs; and fail if no valid containers are
found. Could use a good refactoring.