Initial work on arrow that will point towards the selected stop.
Change to fixed size of arrow view.
Working arrow that points to north, refactor sensor code for list view and arrow into its own centralized OrientationManager.  TODO - point arrow to nearest stop location, update distance text.
Refactor OrientationManager from Singleton into normal class that's instantiated from ArrivalsListActivity, since otherwise its awkward to start/stop updates for onResume and onPause.
Refactor helper class name for orientation, so its not confused with the system classes.
Working distance measure, using LocationHelper to get ongoing best location and update other listeners.  Revert accidental changes to UIHelp.  TODO - point arrow to nearby stop.
First attempt at working arrow pointing to closest bus stop.  Add magnetic correction for compass.
Increase margin above card footer that contains stop name.
Add fading edges to ListView to more closely match "ok, glass" list appearance.
Add mod function to make sure heading stays between 0-360 when calculating heading differences with magnetic declination and bearing to stop.  Force compass redraw when new location is calculated.
Replace code with pre-existing method.
Move distance and arrow so they are bottom-aligned with stop name and bus icon.