A few other files were touched as well as they were referred to by files
in the MIDI part, which lead to other connected things being pulled in.
As this is only the first pass, there will be more necessary changes
coming in the near future. Also, the lowest two levels of structure
were mistakenly removed from the build system; these have been added
back as they are necessary to keep the structure of the manual sane.
This includes fixing em-dashes, badly spaced colons, various
misspellings, removal of spurious {% %} constructs, conversion of <br />
to <br> (still too many <br>s kicking around), and initial light cleanup
of a few sections that caught my eye.
