Notetracking was used in two completely different meanings: the
pitch/bpm notetracking in the delay unit and the cursor follow in
when playing. The word for the second meaning was changed to Follow,
to avoid confusion.
The Model was getting unmaintanable mess. This is an attempt to refactor/rewrite the Model so that data of certain type is exposed in standardized way, offering certain standard manipulations for that data type, and on the GUI side, certain standard widgets to tied to that data.
This rewrite closes#72, #106 and #120.