Proposal: rename pedals indications [patch attached]

[Valentin Villenave]

Greetings,

a few weeks ago, we renamed \fatText and \emptyText in \textLengthOn
and \textLengthOff -- very sensible.

Now, here's another proposal: currently, pedal instructions are
\sustainDown -- \sustainUp,
\sostenutoDown -- \sostenutoUp

What about using, instead:
\sustainOn -- \sustainOff,
\sostenutoOn -- \sostenutoOff

This way, there would be no confusion possible with \stemUp and such.

(any pianist knows that pedal indication are actually always printed
below the staff; but it's more a matter of internal consistency).

Attached is a patch to change that (including convert-ly rules). Feel
free to comment (actually, I do not really care that much about the
Pedal thing; I just wanted to practice writing convert rules :-)

Cheers,
Valentin