Log Message:
Update mathomatic to 11.2.

Changes since 11.1c:

Moved notification of polynomial factoring success to debug level 1 or higher.

Removed "NO_COMPLEX_ROOTS" compile-time define option.
I am thinking of making this a run-time option.

Increased security of "SECURE" compile-time define.
Absolutely no file operations are allowed or linked in.

Added check for terminal with isatty().
This allows better piping into Mathomatic.

Split up change-log ("changes.txt" and "changes_old.txt").

Changed "x!" to mean gamma(x+1) for Laplace transforms.

Fixed parsing of things like "2e#", which failed before,
thinking it was scientific notation.

Wrote "primes/twin.c", to find twin primes.

Added "help usage" command.

Allow output of "help" command to be redirected to a file.

Fixed parsing of variable names (like "pig", which didn't work right).

Added "integrate" command.

Fixed "derivative" command.

Code cleanup.

Fixed "taylor" command.