Gang Mode for TG

# Adds the first iteration of Gang Mode for TG
- 2 or 4 players will be selected to be the bosses of two different gangs.
- They will be able to convert via flashing
- Gangsters (converted crewmembers) will only be able to see the icon of their bosses
  - Gang bosses will be able to see icons for everyone in their gang
- Gang bosses are supplied with a shuttle recaller that can recall the shuttle from anywhere on-station
  - Recallers still need to be used before the point of no return
  - Recallers will send a tracable signal, and communications consoles can know where they come from
  - Recallers can only be used by Gang Bosses
- Gangsters can be reformed (de-converted) by striking them at their head a good few times

### Round-Ending Conditions:
- Gang Victory: The opposing gang's bosses are all dead/off-station/non-human
- Station Victory: The station is successfully evacuated

### Differences from Rev:
- Symmetrical opposing sides (Rev vs Rev, rather than Rev vs Security)
- Heads can be converted (But cannot start as a gang boss)
- Loyalty implants block conversions, but will not de-convert those who are already gangsters
- Not always knowing who is with which gang
  - Lack of membership visibility encourages gangs to stick together and work as a group to avoid friendly fire
- Evacuation as a possible round-ending condition

This has been tested on a locally hosted server of 10 players and it's been found to be bug-free (as far as we could tell).

***NOTE: I ask that admins please DO NOT add this to rotation yet, and DO NOT run it unless I am online to observe the events. The game mode has yet to be fully playtested live, and carries with it a very high risk of it being boring/stupid/buggy as shit. 
I intend to iterate on this at a relatively rapid pace until I'm confident enough to have it in rotation. What I have here is just the game mode in its most basic form. Content will be added/changed in the future if necessary.***

Oh, I also included some bugfixes and other improvements to revolution code.
I also fixed the bug where revheads would sometimes have the regular rev icon instead of their blue one.
I'm not very good with HUDs, but @Rockdtben may have something to say about this?