[PythonCAD] More good stuff at the repo

[Art Haas]

Hi.

As the subject stated, there's more good stuff now available at the
public 'svn' repository. Most of the changes are, as has been the case
lately, undo/redo related. There have been some adjustments to the Log
classes for TextBlocks, DimStyles, and Dimensions, and at long last the
addition and deletion of Chamfers and Fillets is undoable and redoable.
The chamfer/fillet stuff seems to have a slight redraw issue that
suggests the reconnected segments don't share an endpoint - I'm working
on finding what's going on with that right now.  Some chamfer/fillet bugs
were fixed when working on this, btw.

Also, a new set of methods to complement the startUndo(), endUndo(),
and inUndo() methds were added. Amazingly enough these new methods
are startRedo(), endRedo(), and inRedo(). Their purpose should be
self-evident by their names, and right now only the Layer class
is using the new redo methods, but you'll find changes in the various
Log subclasses where these new methods have been added.

It's looking like next week will see the next release as getting
this chamfer/fillet stuff in will probably be the last thing to tackle
prior to release.

PythonCAD turns two next week!

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