Added Separators

Added Separators to BusMapsPage and MyMapsPage and adjusted the heights
of the items.
Fixed DeparturePage

Text no longer visible outside of its widget, also removed magic numbers
form DeparturePage so it should look fine on all screen sizes. Updated
changelog to reflect this.
Added a widget to notify user

Added a widget to MyMapsPage and BusMapsPage to notify user about
opening maps extrnally as it might take some time and user expects some
sort of response to the tap/click gesture.
Added BusyIndicator to BusMapsPage

A BusyIndicator on BusMapsPage now indicates when BusLogic is
downloading its data for BusMapsPage's model.