Composer update

The IlievGK piece (#727, A_Childs_Wish.ly) should be reviewed:
* The copyright was changed from Creative Commons Attribute 2.5 to 3.0
* The original specified markup with Time-Roman which wasn't available on my machine so ... I assume isn't available on most open systems. I modified the font list to use DejaVu but perhaps there is a better substitute?

The 2 Pezelius pieces were relatively simple updates.

Another warning: merging this pull request will (should!) cause a rename operation in the ftp hierarchy for these two composers.

Fixes #152