Disable the ring factory

Disable the ring factory as it is not serving any purporse. It was
actually being used by a few people to exploit money. It was allowing to
produce diamond rings for free.  Eventually we should give it a new
role, or delete it.
Change TeamSpeak address
Rework the way keys are dropped, and given to players

- Removed the old Keychain menu, you are now able to drop, and give keys
with the same user-interface flow as other items
- Changed the logic for mobile phone, so that you are able to drop it an
sell it, and it gets removed from your inventory appropriately (you
still get a free phone when you respawn)