Scheduler rearrange logic could be more optimized

There's a case we don't handle in our Scheduler rearrange logic that would be better handled there than before we went to the exhaustive search. We don't try to shift an existing scheduled recording over to another tuner with an open slot in order to make room for a new one. We will swap the recording time if it has other airings...but that's different. I'm not 100% sure this affects systems that have all tuners with the same lineup...but I think it could. SageTV has always had this deficiency..this is nothing new. :)