2.15.16 regtests - pixel comparator

[Phil Holmes]

A few differences of note - in particular span-bar-spacing where we now get 
a collision between the bar line and natural symbol which did not exist in 
2.15.13.  The other attached images are for comment - but I think there's a 
critical regression shown with span-bar-spacing.

--
Phil Holmes

note-head-aiken.png
Description: PNG image

mozart-hrn-3-page2.png
Description: PNG image

beam-break.png
Description: PNG image

baerenreiter-sarabande.png
Description: PNG image

span-bar-spacing.png
Description: PNG image

slur-script.png
Description: PNG image

fret-diagrams-fret-label.png
Description: PNG image