Remove routing information from Grob_info (issue 294330043 by address@hidden)

[dak]

https://codereview.appspot.com/294330043/diff/1/lily/score-engraver.cc
File lily/score-engraver.cc (left):

https://codereview.appspot.com/294330043/diff/1/lily/score-engraver.cc#oldcode160
lily/score-engraver.cc:160: Engraver_group::announce_grob (info);
I guess this is the one.  Instead of START this must be start_end here.
Let's see how much better we fare with that.

An editing error: at first I was confused into thinking Score_engraver
was an engraver (which has different calling conventions).  But
Score_engraver is an Engraver_group.

And when correcting this, I apparently overlooked one use of START.  Too
bad, the change looked for the better I think.  Now somebody just has to
explain why...

https://codereview.appspot.com/294330043/