Note skin, plumber build, source refactor, fixes

- Notes toggle using scribe commands
- New commands to collapse a single note and collapse all notes
- Separation of code into multiple sources
- Various fixes
- Implemented new styles for notes as a "skin" (src/skin/gu-noting.less):

![note-screenshot-2014-09-26](https://cloud.githubusercontent.com/assets/2298529/4418856/247466ee-4564-11e4-9208-e5d39986010d.png)

Welcome to the ugly corner of the codebase.... `unnotePartOfANote` is a messy function doing a messy thing. I plan to have a think of how it could be simplified but I'd prefer leaving it right now, except for splitting this line into a couple of lines for readability. The one nice thing about this line is that it does what it says on the tin.