Added button to clear selected station

Needs needs a lot of UX love
Only autoselect station if none selected
Don't show "ZERO_RESULTS" error
Changed station clear button text to 'clear'

The '&times;' was a little to ambiguous and missable.
Map interaction tweaks

1) show window after panning
2) don't pan to open station when panning around
Nearby button now reselects closest station