* scm/grob-property-description.scm (beamed-minimum-free-lengths):

* scm/grob-property-description.scm (beamed-minimum-free-lengths):
(beamed-extreme-free-lengths): New property.

* lily/beam.cc (forced_stem_count): Count boundary cases too.
(set_stem_shorten): Integer divide bug fix.

* input/mutopia/J.S.Bach/baerenreiter-sarabande.ly: Really expect
6 systems, change warning into error.

* scm/grob-description.scm (beamed-stem-shorten): Shorten 8th
beams same as normal stem (one staffspace), high order beams less
(arbitrary guess).
(beamed-lengths): Standard length for all beams.
(beamed-minimum-free-lengths):