bug#21072: Brave new mark-defun (and a testing tool)

[npostavs]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Actually, AFAIK the normal "many functions" format looks like:
>
>       * filename (functionname1, functionname2)
>       (functionname3, functionname4)
>       (functionname5, functionname6)
>       (functionname7, functionname8): New functions.
>
> we even tried to make the auto-fill code DTRT in the change-log-mode.

Oh, huh, I took the example in CONTRIBUTE (under "Preferred form for
several entries with the same content:") to mean that lines should end
with colon, but I guess that only applies to multiple file entries, not
functions?  The GNU ChangeLog standards do indeed say to end the line
with just a close paren [1].

[1]: https://www.gnu.org/prep/standards/html_node/Style-of-Change-Logs.html