MUS-92 NoteCrossDrawerTest

added a test for the NoteCrossDrawer class. Also added an abstract
Drawer test class which will hold complex assert methods (like
assertBitmap)
MUS-92 NoteSheetDrawerTest

Added tests for the NoteSheetDrawer class
MUS-92 TrackDrawerTest

Added test for the TrackDrawer class
MUS-92 SymbolDrawerTest

- Added tests for the SymbolDrawer class
- renamed all occurrences of NoteSheetCanvas canvas to NoteSheetCanvas
noteSheetCanvas
MUS-92 NotePositionInformationTest

- Added tests for the NotePositionInformation class
- Added a paint object to the AbstractDrawerTest
MUS-92 NoteStemDrawerTest

Added tests for the NoteStremDrawer
MUS-92 NoteBodyDrawerTest

Added tests for the NoteBodyDrawer class
MUS-92 NotePositionInformationTest

Added a few tests to the NotePositionInformationTest class
MUS-92 NoteBodyDrawerTest

Added more tests for the NoteBodyDrawer class
MUS-92 NoteBodyDrawerTest

Fixed a test in the NoteBodyDrawerTest class
MUS-92 NoteBodyDrawerTest

Fixed NoteBodyDrawer tests
MUS-92 NoteBodyDrawerTest

fixed a testcase
Merge pull request #16 from Catrobat/MUS-92_DrawTests

Mus 92 draw tests