Fixed Bug #7646

Fixed changing map zones/flag of a instance map crashing, also added IOT_ (Instance Owner Type) constants to db/const.txt
Special Thanks to purityz for all the help and test scenarios.
http://hercules.ws/board/tracker/issue-7646-bg-mapflag-instance-reloadscript-mapserver-crash/

Signed-off-by: shennetsind <ind@henn.et>