Re: Make format for key changes consistent; minor formatting corrections for affected regtests (issue 10868043)

[dak]

https://codereview.appspot.com/10868043/diff/1/Documentation/changes.tely
File Documentation/changes.tely (right):

https://codereview.appspot.com/10868043/diff/1/Documentation/changes.tely#newcode320
Documentation/changes.tely:320: \clef bass \key es \major es g bes d
Ok, here is a true "can of worms" followup item: in the case where the
\key statement is followed by more material on the same line, it would
make sense to have a _double_ space before the following material.

git grep '\\key [a-z]\+ \\[a-z]\+ [^ {}]'

throws out a whole lot of candidates for that.  We don't do this sort of
double spacing with other constructs, but in the case of \major I find
the resulting progression in the line badly readable.

The previous e\major worked against this visually.  Cramming this
together might not be the prettiest thing but it was effective.

If we don't do this, then it might make sense as a sort of rule to
separate complete music function calls on a line with double space.

Which would mean

\clef bass  \key es \major  es g bes d

in this case.  Now that would be actually a pretty large undertaking to
do in general (though I'd consider it helpful).  But in case of \key, we
might actually want this now in order to avoid people parsing this as
"\key es" "\major es" "g bes d": since the \key statement ends in a
backslashed word, the danger for misparsing is here particularly large.
Of course, if one writes

\clef treble \bar "||" \key es \major  es g bes d

then there is a certain temptation to do

\clef treble  \bar "||"  \key es \major  es g bes d

right away.  But I think that \key is the worst offender here, and since
it gets worse by this patch, it might seem reasonable to tackle just
that right now.

https://codereview.appspot.com/10868043/