MUS-96 Test refactoring

Changed the drawing tests so that they will be more readable in the
feature (debugging)
MUS-96 Draw refactoring

Split logic from NoteSheetCanvas up into all the drawer classes. Added
a new class NoteSheetDrawer.

Drawing tests will be refactored soon.

Removed some test factory classes because they were not needed.
MUS-101 changed test names

Changed test names on request to give a better overview of what is
tested
MUS-99 Added max track size

Added a feature so that the user can only have a maximal amount of X
elements in a single track
MUS-99 Refactoring

Changed the name of the max track size so that we represent both:
symbols count and note event count (1 Symbol = 2 Note Events)
Refactored NoteSheetCanvas

deleted unuseful code
MUS-99: Text View for track size
Merge pull request #12 from Catrobat/MUS-101_Tests

MUS-101 changed test names
MUS-96 MediPlayer Fixes

- Added a pause mechanism that stops the media players queue if the user
switches apps
- Added synchronized logic to the media player queue
MUS-96 MediaPlayer Bug Fix

- Added a feature that stops the MediaPlayer on user action (open, save,
play all, redo ...)
- Fixed a bug in which the Play all dialog did not disappear after a
context switch (user presses search button on the phone)
MUS-99: Refactoring
Merge branch 'develop' into MUS-96_DrawPerformance
MUS-99: try to fix jenkins issues#1
Merge branch 'develop' into MUS-96_DrawPerformance
MUS-99: try to fix jenkins issues#2
Update build.gradle
Restore build.gradle
Merge pull request #17 from Catrobat/MUS-96_DrawPerformance
Merge develop
Merge pull request #14 from Catrobat/MUS-99_DrawPerformance

Mus 99 draw performance