+20210619
+ + improve configure-macro used for dependencies of --disable-leaks such
+ as --with-valgrind
+ + trim trailing blanks from files
+
+20210612
+ + fixes for scan-build, valgrind build/testing.
+ + update config.guess
+
+20210605
+ + add a summary of ncurses-specific preprocessor symbols to curses.h
+ (prompted by discussion with Peter Farley, Bill Gray).
+
+20210522
+ + regenerate configure scripts with autoconf 2.52.20210509 to eliminate
+ an unnecessary warning in config.log (report by Miroslav Lichvar).
+ + add a note in manual page to explain ungetch vs unget_wch (prompted
+ by discussion with Peter Farley).
+ + add sp-funcs for erasewchar, killwchar.
+ + modify wgetnstr, wgetn_wstr to improve compatibility with SVr4 curses
+ in its treatment of interrupt and quit characters (prompted by
+ report/testcase by Bill Gray)
+ + update config.guess, config.sub
+