int clean_up(arg);
int arg;

clean_up is an l_fun called by the parser.          /* BACKEND.C */
usefull for items to self-destruct ...

The argument passed to the routine indicates the item was a cloned item.
For castles, the "clean_up" routine will NOT be called (921103 Herp)

When the object is loaded, the parser will recognize that a function with name
"clean_up" exists in the object and set its internal flags accordingly.
After loading, clean_up will be called after a certain time. This value is
2 hours at the moment, but may be changed for administrative matters.

Usually, "/room/clean_up" is inherited by the standard room. Of course u can
overwrite this function, and use it in other objects than just rooms.
