Third-person hold stance is now consistent with first-person (held with 2 hands), to match Gmod update

Added ttt_combine_sniper_detective and ttt_combine_sniper_traitor convars to control whether the combine sniper can be bought by detectives or traitors

By default only traitors can buy

Added convars to set how long the combine summoner lasts

- Fixed lua error with removing the combine sniper
- Improved weapon description
- Added convar to have the sniper rotate on the spot
- Summoner now removes itself on use
- Summoner now takes up the proper slot for traitor weapons

Initial addon creation.