+20210904
+ + modify linux3.0 entry to reflect default mapping of shift-tab by
+ kbd 1.14 (report by Jan Engelhardt) -TD
+ + add historical note to tput, curses-terminfo and curses-color
+ manpages based on source-code for SVr2, SVr3 and SVr4.
+ + minor grammatical fixes for "it's" vs "its" (report by Nick Black).
+ + amend fix for --disable-root-environ (report by Arnav Singh).
+ + build-fix for compiling link_test
+ + drop symbols GCC_PRINTF and GCC_SCANF from curses.h.in, to simplify
+ use (Debian #993179).
+
+20210828
+ + correct reversed check for --disable-root-environ (report/analysis
+ by Arnav Singh, cf: 20210626).
+ + apply gcc format attribute to prototypes which use a va_list
+ parameter rather than a "..." variable-length parameter list
+ (prompted by discussion in a tmux pull-request).
+ + modify configure scripts to filter out redefinitions of _XOPEN_SOURCE,
+ e.g., for NetBSD which generally supports 500, but 600 is needed for
+ ncursesw.
+ + improve documentation for tparm and static/dynamic variables.
+ + improve typography in terminfo.5 (patch by Branden Robinson).
+
+20210821
+ + improve tparm implementation of %P and %g, more closely matching
+ SVr4 terminfo.
+ + move internals of TERMINAL structure to new header term.priv.h
+ + add "check" rule for ncurses/Makefile
+ + corrected tsl capability for terminator -TD
+ + add check in tic to report instances where tparm would detect an
+ error in an expression (cf: 20201010).
+ + correct a few places where SP->_pair_limit was used rather than
+ SP->_pair_alloc (cf: 20170812).
+ + fix missing "%d" for setaf/setab code 8-15 in xterm+direct16 (report
+ by Florian Weimer) -TD
+ + fix some documentation errata from OpenBSD changes.
+ + update config.sub
+