Simple Titles change

[Richard Shann]

Simple Titles have long had a problem with showing titles twice over in
some circumstances. I've comprehensively fixed this now.
One thing that is changed: before the Score Title and the Movement
Title were the same font-size, now the Movement Title is slightly
smaller.
As a bonus the coding for the movement titles is now editable at the
start of the LilyPond view so the more techie inclined can tweak the
appearance quite easily there.

Richard