- Disable pcre support for now (boo#1183960, boo#1184083)

- Add ncurses patch 20210327
+ build-fixes for Solaris10 /bin/sh
+ fix some cppcheck warnings, mostly style, in ncurses test-programs,
form and menu libraries.

- Add ncurses patch 20210323
+ add configure option --enable-stdnoreturn, making the _Noreturn
keyword optional to ease transition (prompted by report by
Rajeev V Pillai).

- Enhence cursescheck script

- Disable _Noreturn usage as it breaks build of e.g. dialog

- Add ncurses patch 20210320
+ improve parameter-checking in tput by forcing it to analyze any
extended string capability, e.g., as used in the Cs and Ms
capabilities of the tmux description (report by Brad Town,
cf: 20200531).
+ remove an incorrect free in the fallback (non-checking) version of
_nc_free_and_exit (report by Miroslav Lichvar).
+ correct use-ordering in some xterm-direct flavors -TD
+ add hterm, hterm-256color (Mike Frysinger)
+ if the build-time compiler accepts c11's _Noreturn keyword, use that
rather than gcc's attribute.
+ change configure-check for gcc's noreturn attribute to assume it is
a prefix rather than suffix, matching c11's _Noreturn convention.
+ add "lint" rule to c++/Makefile, e.g., with cppcheck.