project libraries update.
Merge pull request #802 from ne0fhyk/feature_libraries_update

Project libraries update
Starting to work on the follow-me UI
Android: Fixed wrong id on buttons.
Follow: By default use Leash for follow me, with 2Hz update rate
Merge pull request #808 from arthurbenemann/FollowImprovements

Follow detail fragment
Preferences: Have logging enabled always.
Preferences: Automatic format by eclipse
Preferences: Shuffling preference items around to close #809
Merge pull request #815 from arthurbenemann/issue809

Issue809
USB: Adding support for direct connections to the Pixhawk.
Merge pull request #816 from arthurbenemann/pixhawkUSBdirect

USB: Adding support for direct connections to the Pixhawk.
adding support for continuous integration via travis ci.
updated gradle build files to allow for a successful build process.
adding travis ci build status to the README file.
testing travis ci deployement of the built apk files.
updated travis ci script.
updated travis ci script.
attempt to fix travis ci build issues.
attempt to fix travis ci build issues.