BWV 988 var03 Update

bar 5-6 middle voice "d" should be tied
bar 15-16 middle voice "a" should be tied
(Steve Shorter)
Correct unterminated tie warnings
(Felix Janda)
Update to v2.16.1
beam direction and shape
stem length adjust
show accidentals
vertical system adjustment
(Javier Ruiz-Alma)
Close #58