Added station and map activities

Currently, all stations are loaded onto the list view but this crashes
at least the Paris station as there are too many. Need to show only
part of the list at a time.

Map activity has ability to ask for directions by clicking on markers.
Added pretty printing for the stations activity

Might’ve gone overkill on it.
Prettified, added location based sorting, and fixed Paris

Paris was apparently crashing due to the json string being too long to
pass through the intent’s extras. Now using a data handler singleton to
transfer the data instead.

ListView elements are now sorted to give some semblance of order.
Stations are sorted by their proximity to the user, if possible.

Reworked StationActivity’s ListView elements.

Added icons and logos, some basic styling across the app.