musicxml2ly: Emit bar checks for all voices (issue 553620043 by address@hidden)

[nine . fierce . ballads]

https://codereview.appspot.com/553620043/diff/581760043/scripts/musicxml2ly.py
File scripts/musicxml2ly.py (right):

https://codereview.appspot.com/553620043/diff/581760043/scripts/musicxml2ly.py#newcode2287
scripts/musicxml2ly.py:2287: if n._measure_position == Rational(0) and n
!= voice._elements[0]:
Is the purpose of n != voice._elements[0] to avoid printing a bar check
at the beginning of the first measure?  If so, I would have been less
puzzled if the comment were "print a bar check at the beginning of every
measure after the first" or simply "print bar checks between measures".

LGTM.

https://codereview.appspot.com/553620043/