PlayerPROKit: Fix a bug that prevented Music Objects inited with a driver.
For whatever reason, it was always returning nil.
Only set the file path of a Music Object when it's inited as a MADK file.
Minor changes:
PlayerPROCore: don't change the numInstru struct when saving: just use the temporary header already there.
PlayerPRO 6: use the error value passed from readFromURL in PPDocument.
Spotlight: modifying comments.