Mavlink connection with an activity should be stoped when the activity is stoped.
Updating google Play library
Moving almost all the mavlink functions to a library.
Adding a flight path indicator.

Closes #16.
Clear Track menu item to the Flight Data Activity.

Improves for the issue #16.
Adding a Wakelock to keep the display on while connected.
Close #3
Fixing drone marker heading direction, to compensate for the map rotation.
Add a limit to the fligth track length.
Guided mode with long click on flightData fragment.

Still need improvements

Issue #20
Fixes negative heading values in some map rotations.