don't crash if no view has been created when changing network providers
use Android ActionMode for selecting trips
fix crash when no result was returned for QueryMoreTrips
add icons for light theme and API < 11
turned TripDetails into a Fragment
make trip details fold out as fragments in trip activity
fix crash on some devices when starting TripDetailActivity
implement sharing trips as text/plain

closes #21
improve trip layout, make showMore button easier to hit
bring back show platforms button to new TripsActivity
implement action to add trips as calender events