map: added BaseMapActivity for choosing station click action
map: BaseMapActivity uses dataSelection extras
map: added river to Station object
dataselection: added choosing station via  map after river selection
map: filter stations with no water levels from map
dataselection: go to final screen when clicking on map after river
dataselection: map has same enter / exit anims as regular lists
maps: fixed some enter / exit animations
map: added hack for backwards animation

The real solution would be to convert all activities to fragments. That
way each major screen (data, alarms) would have its own activity with
its own custom back animation --> no hacks anymore