Log Message:
Update mathomatic to 12.3.3.

Changes:
  - Yet another improvement to the simplify command.  poly2_gcd() was fixed.
  - Improved bounds checking for gcd().
  - Pause command now takes an argument.
  - Made derivative, extrema, and integrate commands work with non-equations.
  - An important optimization was made to factor_times().
  - Added and tested code for numerical integration.  Currently disabled,
    to enable define "NUMERICAL_INTEGRATE" in CFLAGS.