Swing Playback implementation using staff texts

Individual commits : 
added swing tab

swing settings tab in staff text properties

Implemented step 2 of swing implementation using staff texts

Added call for updateSwing in stafftextproperties

Initial page for dialog changed

System flag enabled for swing parameters

saving and loading with text specified swing implemented

removed extra print statement

fixed formatting

Added groupbox to make the default behavior to no change in swing

fixed indentation in stafftextproperties

fixing conflicts in staff.h

Removed writing of setSwing to file

Removed SwingParameter member from staff and fixed layout of swing tab in dialog

fixed the issue with disabled controls

Added tests for staff text implementation of swing playback

cleaned up the code

Swing playback using staff texts implemented, facilitating local control over swing parameters and tests for the same added