Merge changes Ia8df7446,I77c8d1a7,Iaad492fd,I87fd25f2,I4f534572, ...

* changes:
  Fix sed backslash parsing in square bracket pattern sections.
  Another cleanup pass on printf.
  Move fflush() checking to xexit() and have exit paths in main() call that.
  Cleanup pass on printf.
  Need to update install.c for the changed OLDTOY() argument list.
  Tweak status.html
  Switch a lot of strncpy() calls to xstrncpy().
  strncpy(optptr, hname, strlen(hname)) is really just strcpy().
  strtol() doesn't return error indicator for overflow, it just sets errno. So add estrtol() (which clears errno first), and xstrtol() (which error_exit()s on overflow).
  Debris from flag handling rewrite: don't allow -^A to actually trigger.
  typo fixes
  Fix for mix from Isaac Dunham (who can actually test it). (I tweaked the curly brackets.)
  Redo option parsing infrastructure so #define FORCE_FLAGS can unzero flag macros for a disabled command (needed when multiple commands share infrastructure with a common set of flags).
  When CP_MORE was disabled, the d flag was still in the [-exclusion] list at the end and option parsing fell off the end looking for it (segfault) if DEBUG wasn't enabled to check for that.