Random Notes Generator

As requested by ovingerhagen, here is the start of a random music generator.

It's very much a work in progress & this is just the start.
There are many issues to resolve, including:
- When you call newScore() and request a number of measures, why does MuseScore often create a different number? Does it have something to do with the time signature?
- More validation of the fields.
- Margin round the main dialog box to improve the way it looks.
- Label text black.
- Text input fields bigger.
- How can I specify to addNote() that I want a note to be displayed as a sharp or flat? e.g. pitch 61 coud be D# or E flat.

Anyway it will soon be wine O'Clock, so that's all for now.