Add group system

Initial commit, not tested in multiplayer yet. Some revisions still left
to do.

SQF/dayz_code/groups/kickFromGroup.sqf

@@ -0,0 +1,15 @@
+private ["_myGroup","_target","_targetUID"];
+
+disableSerialization;
+_myGroup = findDisplay 80000 displayCtrl 2;
+_targetUID = _myGroup lbData (lbCurSel _myGroup);
+_target = _targetUID call dayz_getPlayer;
+
+if (isNull _target or _target == player or player != leader group player) exitWith {
+	_this ctrlShow false;
+};
+
+[_target] join grpNull;
+
+PVDZ_Server_UpdateGroup = [2,player,_targetUID];
+publicVariableServer "PVDZ_Server_UpdateGroup";