Update BWV-988 var10

\time 4/4->2/2
bar 11-12: 3rd voice (is now in treble clef for 2 notes) "e2" should be tied over
bar 26-27: 2nd voice "g" should be tied over
(Steve Shorter)
Bar 11-12: set "e"s to the upper staff as shown in source
(Felix Janda)
Update to v2.16.1
Adjust rest positions, tie direction
Bar1: bass: second note prall->prallprall
Bar5: bass: top voice 2nd note prall-> prallprall
Bar9: treble: 1st voice 2nd note prall-> prallprall
Bar13: treble 2nd voice 2nd note prall-> prallprall
Bar15: treble low "a" to lower staff
Bar17: treble \mordent->\upmodent
Bar21: treble \prall->\prallprall
Bar24: treble 2nd voice 1st 'g' add prall
Bar25: prall->prallprall
Bar29: prall->prallprall
(Javier Ruiz-Alma)

Close #62