Update Bach BWV-988 var13

bar24: treble clef, lower voice missing d#
(Steve Shorter)
bar24: missing rest
Correct unterminated ties
(Felix Janda)
Update to v2.16.1
bar6-7: bass top voice missing tie on 'g#'
bar9: bass fix beaming on lower voice 8ths
bar11: treble clef, add staccato to 16th notes
bars 13 & 14: treble, add staccato to 1st note
bar16: treble, move notes to 2nd voice
bar18: treble, remove tie on last 'c' of 2nd beat
bars 21 & 22: treble: add staccato to 1st note and slur rest of 1st beat
bar23: treble: add staccato to 1st note of each beat; bass: remove beam on top voice
bars 29, 30, 31: treble: add staccato to 1st note of each beat
bar32: typeset at 3 voices
(Javier Ruiz-Alma)

Close #63