Code cleanup.
12/28/10 - A possible bug was fixed when entering non-ascii characters.
Added "compare approximate" command option, use of which is more likely to
result in a successful comparison. Runs the approximate command on
both expressions before comparing, if needed.
1/01/11 - The variables command syntax was upgraded to be the same as the code command.
All copyright dates updated to include the new year 2011. Happy New Year!
1/03/11 - Added code to delete identities in the optimize command. When identical
equations were optimized, identities would result. These are now removed.
1/04/11 - Added matho to the mathomatic man page; rmath was already there.
Fixed incorrect syntax in the menu files in menu directory,
thanks to Sandro Tosi for reporting the error and packaging for Debian.
Moved the PDF manual from "doc/manual.pdf" to "manual.pdf", so that it will
be installed separately from the HTML documentation.
1/06/11 - Added "tests/quartic.in". At last, a working set of equations for calculating
the four solutions of any quartic equation, similar to "tests/cubic.in".
1/09/11 - Fixed parser routine to give a helpful error message when a cursor or function key
string is encountered. Escape, carriage return, and form-feed are ignored now.