bug#46979: Allow setting Man-default-entry via Local Variables

["積丹尼 Dan Jacobson" <jidanni@jidanni.org>]

Let's see, one would usually want "make" man and INFO pages when
browsing a makefile. (Ah, we see we want to make a hint about what INFO
page we want too!)

Nobody knows what man pages when browsing a .txt or .html file.

Too many pages when browsing a perl file. OK maybe e.g., Math::Trig if
that is the only "use" used.

Probably no especial page when browsing (oops, I mean editing. Same
above too) a .kml file.

So yes, some alists might be possible. But still... there should be a
way of letting the user use Local Variables per file...

My main use case example is getting


              # field          allowed values
              # -----          --------------
              # minute         0–59
              # hour           0–23
              # day of month   1–31
              # month          1–12 (or names, see below)
              # day of week    0–7 (0 or 7 is Sun, or use names)

reminders that I put in out of my crontab files.

And

# man Mail::SpamAssassin::Conf
# man spamassassin-run

out of my spamassassin files... (which are meant for me to put the
cursor on and do M-x man.) (so we see here we want to put two items on a
list of man page defaults!)

>>>>> "DM" == Daniel Martín <mardani29@yahoo.es> writes:
DM> Do you have a more complete list of potential use cases...