This addresses https://savannah.gnu.org/bugs/?48992.

After commit e739448c, macros should work also when ncurses produces
escape sequences instead of keycodes.

If the user uses a single version of nano, they have no need for
--quiet.  If they do sometimes use an older version and don't want
to see the warnings, they can use 2>/dev/null (they could make an
alias for that and put it before the call of nano).

Date and version are updated to match each release, so the user does
not have to wonder whether the man page really describes the binary.

Also remove a bit of superfluous markup.

This is no longer accurate.

Rename the corresponding rc-file option too, of course.

In nano, -a is only effective when also -$ is given, so this will
not conflict with Pico since Pico does not know the -$ option.

The dash doesn't have to be the first non-option argument: it can
be anywhere among the filenames -- there can even be multiple ones
(but don't mention this explicitly).

Mention some things that really set nano apart from Pico.
Plus some other small tweaks here and there.

The interval 2013-2017 for the Free Software Foundation is valid
because in those years there were releases with changes by either
Chris or David, and the GNU maintainers guide advises to mention
a new year in all files of a package, not just in the ones that
actually changed, and be done with it for the rest of the year.

Also, remove the special "+line,column" argument from among the options,
since it isn't an option -- put it in a separate paragraph instead.

There are just a handful of source files for the documentation --
it is wasteful and cumbersome to have these in separate directories.

Also: remove the French man pages -- they are too far out of date.
(And anyway, we should acquire a general framework for translating
the documentation.)

The nanorc option already exists, but not the corresponding one
for the command line.

It can be activated with --linenumbers on the command line or with
'set linenumbers' in a nanorc file, and it can be toggled with M-#.
Signed-off-by: Faissal Bensefia <faissaloo@gmail.com>
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>