Stuff To Be Implemented/Fixed
-----------------------------

 - Add Polygon
 - Add Ellipse
 - Add Spline
 - Add Text
 - Manipulate Dimension
 - Object connections
 - Group selection (kind done, needs more work though)
 - Take movement code out of Objects and put it into top level Container (actually
   I think this should be more of the state code handling. Have to see.)
 - Add OSD to Object creation
 - Add layers
 - Add blocks
 - Add page layout
 - Add pen color/style/width to Objects
 - Add fill/hatch to Objects
 - Fix zooming to be more intuitive
 - Add other Dimension types, like radial, diametric, leader
 - Mirror tool (started, needs actual mirroring implementation)
 - Restrict movement horizontal/vertical tool
 - Trim tool
 - Fix Arc manipulator. Idea: split edge handles so that the inner half controls
   arc sizing, outer half controls rotation. That way you can grab either handle
   and know what it's supposed to do.
 - Fix loading and saving code
 - Add Drawing Properties dialog (separate from Application Settings)


Stuff That's Done
-----------------

 - Fix snap to grid to honor both states (right now, it's a weird mix of states)
   [Shamus 2013-08-11]
 - Add Arc [Shamus 2013-08-14]
 - Fix snap to grid to allow picking up of handles when they are not on a grid
   point. [Shamus 2013-08-18]
 - Add OSD routines so they don't have to be implemented in Objects [Shamus
   2013-08-24]