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.
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Also: remove the French man pages -- they are too far out of date.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.)