[PythonCAD] Latest updates in repo

[Art Haas]

Hi.

I've sent my latest updates to the public subversion repository. There
are a number of bug fixes - a dumb typo in the gtkimage.py file for
example, as well as a switchover to using the time module instead of the
datetime module in the printing.py file. The datetime is not available
in Python 2.2, so my use of it was in error. There are also the first
set of undo/redo improvements in the changes I sent. The stored values
for the various entities are now stored in a class and not the tuples or
dictionaries as was done before. Also, restoring objects like segments,
circles, arcs, leader lines, and polylines will now restore correctly
the color, linetype, and thickness those entities had when they were
deleted. Previously these entites were recreated with default values.

More undo/redo work with dimensions is on my plate for the next week,
and then adding in some missing print functionality will begin. I'm
hoping to send out the next release in the middle of November.

Art
-- 
Man once surrendering his reason, has no remaining guard against absurdities
the most monstrous, and like a ship without rudder, is the sport of every wind.

-Thomas Jefferson to James Smith, 1822