fix notes, text on 'Es ist ein Ros'

[maiamcc]

Re: issue #3, since I was fixing this stuff for my copy anyway.

Changes:

• text: "war" --> "kam"
• add pick-up, shifted rhythms for better text stress
• note fixes in alto and tenor

Take or leave whatever is useful to you from this diff!

[bbloomf]

I think you changed the wrong note to a whole note in the soprano line in the second commit. Anyway, I committed some changes based on this pull request and the score here http://www3.cpdl.org/wiki/images/c/cd/Praetorius_einros.pdf