Log Message:
Update mathomatic to 12.8.0.

Changes since 12.7.7:
10/10/07 - Proper error reporting for shelling out (! command).
10/12/07 - Created directory "m4" to play with using m4 to allow easily
entering functions through macros.
10/14/07 - Improved "set dir" to display the new current directory and to
default to the home directory.
10/17/07 - Entering "=" by itself now swaps equation sides instead of doing
nothing.
10/18/07 - New "mathomatic.ico" file with transparent background.
10/21/07 - Increased speed of taylor command up to 3 times by not doing an
unnecessary simplification.
           Added "tests/distance.in".
10/22/07 - Fixed a small problem in calculate command, allowing instant
calculation of (2+2i)^99 now.
           Entering any power of any complex number should work now.
10/29/07 - Solving now reports what degree polynomial the equation is.
11/12/07 - Fixed 3 bugs in optimize command.
11/16/07 - Fixed another bug in optimize command.