- Update to ncurses 6.3 (patch 20211021)
+ update release notes
+ add "ncu2openbsd" script, to illustrate how to update an OpenBSD
system to use a current ncurses release.
- Add upstream keyring to verify source signatures of both ncurses
and tack tar ball with their ASC (armored ASCii signature) counterpart

- Add ncurses patch 20211018
+ check for screen size-change in scr_init() and scr_restore(), in case
a screen dump does not match the current screen dimensions (report by
Frank Tkalcevic).

- Add ncurses patch 20211017
+ amend change for pkg-config to account for "none" being returned in
the libdir-path result rather than "no" (report by Gabriele Balducci).
- Add ncurses patch 20211016
+ build-fix for pmake with libtool.
+ improve make-tar.sh scripts, adding COPYING to tar file, and clean up
shellcheck warnings.
+ add link for "reset6" manpage in test-package ncurses6-doc
+ revise configure option --with-pkg-config-libdir, using the actual
search path from pkg-config or pkgconf using the output from --debug
(report by Pascal Pignard).
+ freeze ABI in ".map" files.
- Correct offsets of patch ncurses-6.2.dif

- Add ncurses patch 20211009
+ implement "+m" option in tabs program.
+ fill in some details for infoton -TD
+ fix spelling/consistency in several descriptions -TD