Manual reorg finished

[Graham Percival]

The manual is finished!  The documentation is perfect!  Well, not
quite.  But I'm finished doing all the major work I was planning on
doing on the manual.

- There are a few sections that didn't really seem to fit in anywhere,
and I'm not happy with all the chapter titles.  As always, suggestions
appreciated.
- The "how to use this manual" part of the introduction will be updated
once I'm fairly certain about the titles.
- The new sections could use proofreading.

http://lilypond.org/doc/v2.9/Documentation/


Cheers,
- Graham