Tuplet line-breaking

[Trevor Daniels]

I've been unable to discover how to permit line-breaking
when there is a long sequence of tuplets which cross
barlines.  Beams and Glissandos subscribe to the
unbreakable-spanner-interface, so line-breaking when these
cross barlines may be permitted by setting #'breakable =
##t.  But TupletBracket and TupletNumber do not support this
interface, so this override does not work for them.

Is there any other way, or should I add a caveat to the
section of the manual which deals with tuplets?

Trevor D