Fix #26 - add a "Load More Arrivals" option at the bottom of the
ArrivalsListFragment list.  When pressed, this loads an additional 30
minutes of arrivals.  This process can be repeated to load arrivals in
30 min. increments.  If no additional arrivals are available within the
next 30 minutes, a Toast is shown to the user indicating that there were
no additional arrivals in the next X hours and Y minutes (which can also
be repeated to try the next X hours and Y+30 minutes).
Update to #26 - fix copyright headers.
Update to #26 - Slight increase in padding below "No arrivals in the
next X minutes" text so the top and bottom spacing of the TextView are
symmetrical, and so the TextView height is equal to the normal list item
height when an arrival time is shown.
Merge pull request #84 from CUTR-at-USF/issue26

Fix #26 - add a "Load More Arrivals" option at the bottom of the ArrivalsListFragment list