Testing Appreciated: Editing Multiple Segments in Notation

   Just pushed Philip's fixes to the notation editor for bug 1672 to 
git.  Testing appreciated.  This is a significant change to the notation 
editor UI and we want to get it right.

   The issues were related to editing multiple segments in notation.  If 
you regularly do this, please have a look at the latest.

   Highlighting of the current segment has been improved.  Previously we 
selected the notes for the current segment being edited.  Now we 
highlight them instead.  Highlighting can be controlled via the new View 
 > Highlighting menu options:

- None: No highlighting of the current segment being edited.  This 
setting is useful if you just want to look at the notation without 
highlighting/dimming.

- Current: The current segment being edited appears normal.  All other 
segments are dimmed even if they are on a different track.  This is the 
most extreme form of highlighting.  It makes it very clear which segment 
is being edited.

- Current on same track: The current segment being edited appears 
normal.  All other segments on the same track are dimmed.  Segments on 
other tracks appear normal.  This is closest to the original rg behavior 
and is the default.  It offers a clear indication as to which segment on 
a track is currently being edited.

   Additionally we now allow the position pointer to be placed outside 
of the current segment being edited (e.g. moving it via the ruler at the 
top or stopping playback outside of the current segment).  Not sure if 
this will cause unforeseen problems.  Please test and let us know.

   Full details are in the bug report:

https://sourceforge.net/p/rosegarden/bugs/1672/

Ted.