GDP: preferred terms

[Graham Percival]

I've started a list of preferred terms in policy.txt.  These are words
where people have asked me which spelling/term we prefer, and I don't
want to give different answers to different people.

I think this is a bit late; I'm certain that I've flip-flopped on "bar
lines", but at least this time (once they're added to this list) I won't
change my mind again.


* Preferred terms:
    - in general, use the American spellings.  The internal
      lilypond property names use this spelling.
    - list of specific terms:
canceled
simultaenous    NOT concurrent


There's a few more terms to add to this list:
- "bar" vs. "measure".  Whenever possible, we use the same term as the
internal lilypond syntax uses... but I've seen both bars and measures in
those docs.  Should we just leave this up to individual doc writers, or
pick one word?

- "barline" vs. "bar line".  I believe that the lilypond syntax is
"barline", but that could just be because we can't have spaces in
property names.


As far as I know, nobody (including me) really cares _which_ term we
pick; we just want one answer so that we stop changing each other's text
all the time.

I'll probably be asking for a few more terms in the next week or so.

Cheers,
- Graham