Various build updates from Nelson

* merges:
  Add the new silent-rules options to the list of known configure opts
  Warn about ignored tty 'with' options. Fix if with missing fi
  Add additional tty lib 'with' options
  issue warning when no tty nor window system available
  Enable silent building, ie --enable-silent-rules and make V=0
  Correct the remote configuration command message
  new SXE_CHECK_LINK_LIB macro
  Add summary for additional tty libraries
  Rename git-to-steve -> git-for-steve
  xstrncpy saga
  Better checking of string and memory operations. Also, add define FORBID_STRCPY to make runtime asserts on usage of strcpy, strcat and stpcpy.
  xstrncpy saga
  xstrncpy saga
  xstrncpy saga
  xstrncpy saga