* organized imports
* added test for calculation of unique area for position
* fixed test cases to work
no comments
Moved the Start/Stop etc. buttons from MainFragment to action bar of MasterActivity,
moved reference to current lesson to MasterActivity incl. all business logic related to it,
removed ./tmp directory which slipped to GIT for some reason
Compeletely refactored the layout: splitted it to several **Fragments.

Each fragment is coupled with an appropriate lesson. The fragment for lesson
is created in the factory: FragmentFromLessonFactory.class.
The dialog for instrument selection was added.
The single **Lessons refactored to contain concrete fragments.
Refactoring
Added ScalegridChord2Position lesson and related view
* added Chord-to-Parent lesson
* added KeysView, containing C, C#, ... B keys
* introduced AbstractNotationView for views like DegreesView, KeysView etc.
Added ModeDegree2Parent lesson