Fix #27 - Migrate to Gradle build process and Android Studio.
Fix Gradle release process.
Fix debug signing when the "secure.properties" file exists.
Fix #13 - Add better labeling to the Sky view, including a North indicator and PRN labels for each satellite.  This needs to be combined with the fix for #29 to display proper North direction in landscape mode.
Fix #29 - Use the Sensor.TYPE_ROTATION_VECTOR instead of the deprecated TYPE_ORIENTATION to rotate the Sky display according to compass bearing.
Update to #29 - Fix compass direction when screen orientation change occurs by remapping the coordinate system accordingly.
Fix #26 - Add distinction for GLONASS satellites.  Add flag image to Status view, and show GLONASS sats as squares in Sky view.
Collapse variables of same types into single declaration, fix some formatting.
Only set ImageView scaleType when creating a new ImageView.
Resize Russian flag image to match the exact size of the US flag.
Fix #31 - Rotate map display with compass.  Squashed commit of the following:

commit 50987604b7bd423329a0f4a74b33e4c009eee589
Author: Sean Barbeau <sjbarbeau@gmail.com>
Date:   Thu Jan 23 21:42:12 2014 -0500

    Update to #31 - add preferences for controlling the map based on compass and sensors (tilt).  Some code cleanup and refactoring.

commit 20aa083960eb3479a2832f6ca91257eced20a472
Author: Sean Barbeau <sjbarbeau@gmail.com>
Date:   Thu Jan 23 12:42:20 2014 -0500

    Update to #31 - add NaN check for tilt, since on older phones without the modern rotation vector sensors this could happen.

commit b557ad0b4fa8ca4360cb1bbe2425dcff705a0201
Author: Sean Barbeau <sjbarbeau@gmail.com>
Date:   Thu Jan 23 12:27:14 2014 -0500

    Update to #31 - add listener to "My Location" button, and temporarily disengage map control based on touch on this button as well (button functions as normal now as well).

commit d0bdf39bf8de61d335a1d4dfe42b3e0e35c0c649
Author: Sean Barbeau <sjbarbeau@gmail.com>
Date:   Thu Jan 23 12:16:16 2014 -0500

    Update to #31 - fix map camera so sensor-based movements continue after orientation change.

commit 8ec2d9f19cc6783cfcd31b2dbca7c38ea88b061e
Author: Sean Barbeau <sjbarbeau@gmail.com>
Date:   Tue Jan 21 22:25:15 2014 -0500

    Update to #31 - Change map orientation and tilt based on sensor data.  Also allows the user to tap on the map (long or short) to temporarily exit the automatic map control and manually scroll the map.  Automatic map movements will kick back in after approx. 5 seconds of inactivity.

commit b09800d3d7f84e2bd52c49a3ce023c9733cbedf0
Author: Sean Barbeau <sjbarbeau@gmail.com>
Date:   Wed Jan 15 21:54:48 2014 -0500

    Initial work towards #31 auto-rotate map with compass.  Refactors sensor listener out of GpsSkyFragment and into GpsTestActivity, with all fragments getting orientation updates via GpsTestListener interface.
Fix #32 - Resize compass on Sky View to the proper size by receiving the width and height from the OnGlobalLayoutListener when layout is complete.
Remove tilt map preference if the device doesn't support rotation vector sensors.
Bump versions of Gradle, Android Gradle plugin, and Android Support Library.
Fix #28 - Add support for large screen devices.
Fix #35 - Add a preference link to GPS Benchmark
Fix #23 - Prompt the user to enable GPS if GPS is not enabled.
For sensor onOrientationChanged(), only change Fragment view when that Fragment is visible.  Results in significant performance improvements for medium/small screen devices that use the ViewPager, since only one fragment will be visible at a time.
Refactor old references to "activity" to more generic "listener".
Fix #38 - Fail gracefully for devices without GPS.