Re: Merge-differently-headed can't accommodate three voices

[Graham Percival]

Carl D. Sorensen wrote:
> % merge-differently-headed can only handle two voices
>
> % the first shared note, d''2 and d''8 is shared between voice1 and
> voice2
> % the second shared note, e,8 and e'2, is shared between voice2 and
> voice3
> %  an error message is given, and the notehead is _not_ a half not

Sorry, you were too fast for me -- Han-Wen reported that 
merge-differently-headed was only meant for opposing stem dirs
(ie. Voice 1 & 2). Merging would create incorrect notation here.

I'm updating the docs accordingly.
- Graham