Lfun:	forbid_enter_container - forbid an item to enter a container

Synopsis:
	int forbid_enter_container(object container)

Description:
	The forbid_enter_container function is called in an item before
	it enters a container, for example if a player wants to put it into
	a bag.

Return value:
	Return 1, if the item mustn't enter the container, 0 if it may.

Examples:
	An item that doesn't enter a bag:

	forbid_enter_container(con) {
		if (con->id("bag")) return 1;
	}

See also: object/notify_item_enter, object/notify_item_leave, object/forbid_item_enter, object/forbid_item_leave, object/notify_enter_container, object/notify_leave_container, object/forbid_leave_container, object/drop, object/get, efun/move_object, efun/transfer