Add musicexample.sty

LaTeX package to deal with (lilypond and generic)
music examples.
First working version.

To be done:
- Allow th caption 'name' to be changed from the document
- Optional scaling of images _if they are wider than
  the \textwidth_
- Looping over a set of numbered subfiles
- check the passing of the optional argument
  from \lilypondMFE to \musicMFE
- include the manual example types in the 
  (listof{musicExample}
- adjust layout of float and non-float environments
  and optionally make them user-definable
- Implement scrheadings for use with fullpage examples
- page range for references
- check where the \label is actually placed with afterpage
- If it is possible to determine the number of pages in a 
  pdf document remove the separation of one- and multipage
  examples
- optionally: use a cropped image and scale it to the text area