mint-arena: Get MAX_ENTITIES_IN_SNAPSHOT from CGame
mint-arena: Remove unused uiClientState_t from CG_Cinematic_f
mint-arena: Store connection state globally

Using trap_GetClientState(uiClientState_t *) just to get the connection state is annoying.
mint-arena: Don't use trap_GetClientState when not needed

ClientNums and connection state are tracked in cgame, don't need to make a syscall just to get them.
Fixed some cases when local client 0 is not in-game but other local clients are.
mint-arena: Remove client numbers from uiClientState_t
mint-arena: Remove AS_MPLAYER
mint-arena: Remove CG_EVENT_HANDLING from public CGame API
mint-arena: Move usage of CG_WANTSBINDKEYS into CGame