Detail:
  If ChangeFSI program was used as a BASIC LIBRARY, calls to it would fail with
  "Unknown or missing variable" due to the use of spop% which isn't defined in
  library usage.

  Also fixed install rule in makefile to use "do mkdir -p" rather than "cdir".
Admin:
  Tested - seems to still work!

Version 1.23. Tagged as 'ChangeFSI-1_23'