Log Message:
Update mathomatic to 11.5.

Changes:
  - Using "memmove()" instead of deprecated "bcopy()".
  - Added "tests/tutor.in", which is an incomplete Mathomatic tutor.
  - Many improvements to scripts in the tests directory.
  - Removed "calculate factor" option.
  - Code cleanup.
  - Added more modulus simplification.
  - Simplify ((a%n)*integer+b)%n to (a*integer+b)%n generally and completely.
  - real^complex and complex^complex are now approximated.