Rename vertical spacing dimensions. (issue2303044)

[percival . music . ca]

With regards to convert-ly, it would be nice to run it on the
translations.  But as long as the doc build still works, don't manually
change anything in the translations.

I'll be writing up policies for convert-ly later this evening or
tomorrow.


For the regtests, just go ahead and rename them.  Any regressions in
those files in 2.13.36 won't be picked up automatically, but I think we
have enough eyes on the spacing stuff right now that this isn't a huge
loss.  If you want to be totally safe, then check those specific
regtests manually in the official 2.13.36 release.



http://codereview.appspot.com/2303044/diff/2001/Documentation/notation/spacing.itely
File Documentation/notation/spacing.itely (right):

http://codereview.appspot.com/2303044/diff/2001/Documentation/notation/spacing.itely#newcode11
Documentation/notation/spacing.itely:11: @c \version "2.12.0"
I expected convert-ly to update this number.  Did you deliberately
suppress (or revert) that change, or is convert-ly broken?  :(

In either case, please update the version number here.

http://codereview.appspot.com/2303044/