Log Message:
Update mathomatic to 12.5.17.

Changes since 12.5.15:
Allow curly brackets ("{}") as parentheses.
Allow all taylor command input on the command line.
Add taylor command to tests.
Added -u option (Unbuffered mode).  Previously output was always unbuffered.
Fixed compilation failure with some versions of GCC, when using readline.
Made some nice changes to "gcd.c".
Added "solve" as a command.
Adjust copyright dates and file comments in all source files.
Fix display of -0 (now displays as 0).
Restore matho-sumsq to Prime Number Tools.