Fix several exploitable bugs in the CUserCmd class. Some of these have been used to exploit/cheat in-game. Fixes contain:
- Camera position clamping (the only patch that hasn't been tested yet!)
- Weapon activity exploit, allowing player to infinitely throw ordnances, and perform other 'cheats'.
- Akimbo exploit + server crasher, allowing client to set multiple inventory weapons as active. The active weapon index bounds were also not checked, a properly crafter CUserCmd message would therefore be able to crash the server.
Note that this does not fix all issues related to the UserCmd class; further reversing and testing revealed there is more to be fixed, these fixes will get implemented with a future commit.
