* etc/tutorials/TUTORIAL: Don't keep referring to EDIT as if it were a
common name for the Meta key; since a few decades back it's labelled
Alt (or Option or ⌥ but those keys usually also have 'alt' engraved on
them).  Similarly, CTL is practically extinct and not worth
mentioning.

* doc/emacs/basic.texi (Basic Undo): Document the easiest way to
type the undo key.

* etc/tutorials/TUTORIAL: Describe typing C-_ without the Shift
key.

* etc/tutorials/TUTORIAL: For consistency with C-x s ("save some
buffers") and for accuracy, describe C-x C-s as "Save buffer to
file"), and then C-x s as "Save some buffers to their files"
(bug#39359).  Also capitalize "Dired".

Copyright-paperwork-exempt: yes

Run "TZ=UTC0 admin/update-copyright $(git ls-files)".

Run 'TZ=UTC0 admin/update-copyright $(git ls-files)'.

Run admin/update-copyright.

Most of this change is to boilerplate commentary such as license URLs.
This change was prompted by ftp://ftp.gnu.org's going-away party,
planned for November.  Change these FTP URLs to https://ftp.gnu.org
instead.  Make similar changes for URLs to other organizations moving
away from FTP.  Also, change HTTP to HTTPS for URLs to gnu.org and
fsf.org when this works, as this will further help defend against
man-in-the-middle attacks (for this part I omitted the MS-DOS and
MS-Windows sources and the test tarballs to keep the workload down).
HTTPS is not fully working to lists.gnu.org so I left those URLs alone
for now.