Re: Doc: mention empty chords; avoid using zero-duration spacers in examples (issue 6197068)

[tdanielsmusic]

http://codereview.appspot.com/6197068/diff/1/Documentation/notation/simultaneous.itely
File Documentation/notation/simultaneous.itely (right):

http://codereview.appspot.com/6197068/diff/1/Documentation/notation/simultaneous.itely#newcode89
Documentation/notation/simultaneous.itely:89: r4 e8( g <>) ^"sul D" \f
\> \repeat unfold 8 { c-. } r2\!
> <>\! can only be used if it
> happens to fall on a bar line.

But, as David has pointed out, this is more likely a problem in spanner
management, as c1*0 has exactly the same problem.  So <> is no worse
than s1*0 in this regard.

http://codereview.appspot.com/6197068/