Centring on searched locations adds pins and does not set coords

It looks like it was programmed this way on purpose, as a feature, but given the way you need to use the map widget to set coordinates for a map field, it actually makes it very cumbersome to use. After you have searched and centred on a place, it adds another pin. After a few searches to find the right location, you have a whole bunch of markers on the map and it gets confusing. Not to mention that once you've found the right location, you have to then click around it to get it to actually set, and that moves the pin off the spot a bit.

Instead, centring the map using a search should MOVE the pin, not add a new one, and automatically adjust the coordinates. It might also be nice to have a "reset" button in case you had a starting pin you want to revert to, but that's more of a feature request and not really part of this "bug".

The patch for this is extremely simple. I've already implemented it in my site and have attached my git patch file so you can integrate this change into the next version if you want.