[CM] new chapters...

[Tobias Kunze Briseño]

quick notes:

  - ghosts:
    - seem fine, but note that list-ref is not defined; it appears to be elt,
      but it's not defined in the lisp version
    - maybe a stretch factor of less than 2 would be better, i.e., 
      
        for ahead = (* here 1.5)
        ...
        and sprout ... at (* ahead 1.5)
    
      or so then there is less silence..
  - html:
    - i'd add an "up" link next to the previous and next chapter links
    - the text is all in italics at the end of ch 11
    - i'd add pre-rendered midi (and maybe score) files, for convenience
    - i think html should have more links, that is when you refer to some
      function, a link should take you to the definition of it, sort of 
      like an index would do