+20170909
+ + improve wide-character implementation of myADDNSTR() in frm_driver.c,
+ which was inconsistent with the normal implementation.
+ + save/restore cursor position in Undo_Justification(), matching
+ behavior of Buffer_To_Window() (report by Leon Winter).
+ + modify test/knight to provide the "slow" solution for small screens
+ using "R", noting that Warnsdorf's method is easily done with "a".
+ + modify several test-programs which call use_default_colors() to
+ consistently do this only if "-d" option is given.
+ + additional changes to test with non-standard variants of curses:
+ + modify a loop limit in firework.c to work around absense of limit
+ checks in some libraries.
+ + fill the last row of a window with "?" in firstlast if waddch does
+ not return ERR on the lower-right corner.
+ + add checks in test/configure for some functions not in 4.3BSD curses.
+ + fix a regression in test/configure (cf: 20170826).
+