Re: Align metronome mark at time signature or first musical element. Fixes #684. (issue1579041)

[n . puttock]

http://codereview.appspot.com/1579041/diff/30001/31004
File lily/metronome-engraver.cc (right):

http://codereview.appspot.com/1579041/diff/30001/31004#newcode82
lily/metronome-engraver.cc:82: && g->get_property_data
("break-align-symbol")
text_->get_property ("break-align-symbol")

OK, so it's unlikely, but a user might use a callback to set
'break-align-symbols instead of a simple list.

http://codereview.appspot.com/1579041/diff/30001/31004#newcode88
lily/metronome-engraver.cc:88: text_->get_property_data
("break-align-symbols"))
get_property ()

http://codereview.appspot.com/1579041/diff/30001/31004#newcode112
lily/metronome-engraver.cc:112: text_->get_property_data
("non-break-align-symbols"))
get_property ()

http://codereview.appspot.com/1579041/diff/30001/31008
File scm/define-grobs.scm (right):

http://codereview.appspot.com/1579041/diff/30001/31008#newcode1159
scm/define-grobs.scm:1159: (non-break-align-symbols .
(multi-measure-rest))
+ (non-musical . #t)

http://codereview.appspot.com/1579041/show