mint-arena: Expose control of more bot trace contentmasks to Game VM

Also expose pass entity num for AAS_DropToFloor.

To maintain the same behavior in game VM;
  - AAS_DropToFloor: Use passent 0, contentmask CONTENTS_SOLID
  - Others: Use contentmask CONTENTS_SOLID|CONTENTS_PLAYERCLIP
mint-arena: Fix double team change message

Only print team change in ClientBegin if first spawn.
ClientBegin is called at connect and team change.
Merge remote-tracking branch 'mint-arena/master'