T:flagset( flag [, value] )
Arguments:
**flag** - string value.
**value** - boolean value. Optional argument, true by default. Designates whether the flag is to be set or unset.
Return value: none
Set or unset the given flag on the lua object.
Example:
mob:setact("safe")
mob:say("I'm safe now.")
mob:setact("safe",false)
mob:say("Now I'm not safe.")