Preferred use of define-grob-properties.scm

[Carl Sorensen]

Currently, define-grob-properties.scm is (almost) alphabetical by
property.  This makes it nice for avoiding the collisions that occur
when two different grobs have a property with the same name, but makes
it very difficult to see all the properties associated with a given
grob.

Would it make sense to order the properties alphabetically by the grob
to which the property applies?  That is, should we have all fret-diagram
properties adjacent to one another?  I suppose that if a standard were
developed such that the property names began with the grob name, there
would be no conflict between alphabetically and grouped by grob name,
but renaming all of the properties seems to me to be a low priority.

I've just added the properties for fret-diagrams, and they're scattered
throughout define-grob-properties.scm.  I'd be happy to collect them in
one section if it's preferred.

Thanks for your input,

Carl Sorensen