Fix #189: Episema over single neume. (issue186189)

[hanwenn]

lgtm.

just a quick look at at the .cc


http://codereview.appspot.com/186189/diff/2001/2005
File lily/episema-engraver.cc (right):

http://codereview.appspot.com/186189/diff/2001/2005#newcode92
lily/episema-engraver.cc:92: announce_end_grob (finished_, SCM_EOL);
this should point to the STOP event

http://codereview.appspot.com/186189/diff/2001/2005#newcode101
lily/episema-engraver.cc:101: Episema_engraver::typeset_all ()
typeset_finished() ?

http://codereview.appspot.com/186189/diff/2001/2005#newcode114
lily/episema-engraver.cc:114: if (span_ && !span_->get_bound (LEFT))
what if note_cols is empty?

http://codereview.appspot.com/186189/diff/2001/2010
File scm/define-grobs.scm (right):

http://codereview.appspot.com/186189/diff/2001/2010#newcode746
scm/define-grobs.scm:746: line-interface
episema-interface ?

http://codereview.appspot.com/186189/show