Move musicexamples to ded. folder

musicexamples.sty isn't a single package file but will consist of
- the LaTeX package
- LilyPond (configuration) stuff
- Python script(s)
- Documentation

So it should be in a dedicated folder
(like one where lilyglyphs might go)
musicexamples: Implement lilypondMFE

Multi-system-examples (LilyPond)

Assume the output of a LilyPond generated multi-system example
-> one image per system
- counting/naming scheme from lilypond-book-preamble
- -systems.count file present

read the number of systems from -systems.count
loop through them and include the image files
musicexamples: change float to newfloat

Use the (better)newfloat package to create the
floating musicexample environment.
musicexample: Make float captions left-aligned