add: LOG(L_ERR, "removed watcher %p (pres %p)\n", _w, _p);
context: int remove_watcher(presentity_t* _p, watcher_t* _w){	watcher_t* watcher, *prev;	watcher = _p->watchers;	prev = 0;		while(watcher) {		if (watcher == _w) {			if (prev) {				prev->next = watcher->next;			} else {				_p->watchers = watcher->next;			}			return 0;		}		prev = watcher;		watcher = watcher->next;	}		     /* Not found */	DBG("remove_watcher(): Watcher not found in the list\n");	return 1;}