Stop spurious bar lines for large \partial commands

Stop spurious bar lines for large \partial commands

Previously \partial commands exceeding one bar of length led to
gratuitous bar lines inserted at multiples of the current bar length.
This stops the Default_bar_line_engraver from inserting bars in these
situations.  This allows using \partial for inserting large
intermediate bars without requiring meter changes.

[dak, 2018-02-20 19:40:53]

Fix non-bar when some material takes a multiple of whole measures