Change geo's find to end of search

With the new `balancing' and emphasis on iron production, I think it would be very helpful if the geologists could find exhausted deposits at the `end of their search' rather than only find new ones from exhausted ones from the time they are sent out.
Without Jollies, players will not have coal production from coal mines for four hours, so I think a `re-balancing' is in order and allow the more organised players to benefit, by sending out geo's in advance. Either that or shorten the time generally for iron and coal searches. How about it BB, a tweak in favour of the players right now might restore some faith ;)

something like that is already in place i think, i do make use of it with marble at least, but no idea if it works with coal.

one thing for sure to make it work is that a deposit needs to be empty when the geo is done searching, but i usually send out my geo when the deposit will go empty halfway of the search. might be something to try out for coal, never tried it there.