updated to use RX extensions

* big change to the app; using RX extensions
* stations list and favorites are updated when the city changes if it's
set to -automatic-
* the route to station is recalculated if you're moving
- removed unused code
+ added a CityContext class that handles the current city, its stations
and favorites
* updated packages; might ignore the packages as they can be upgraded
from the project and they just add up to the repository size
+ added a new logo and images
+ added google maps geocoding