Support for colored pens (already available for drawing lines, still has
to be enabled for filled shapes).
Support for separate edge and face colors. Named objects.
- The default property is renamed "format" (instead of "color"). Its
format is a string like "--red[blue]", where '--' is the LineStyle (not
implemented yet), 'red' the EdgeColor, and 'blue' the FaceColor.
- Colors can also be set with the "EdgeColor" and "FaceColor" properties
- Implemented the "name" property, to provide support for named objects
(not tested yet).
Merge pull request #52 from dvinc/master

Support for separate edge and face colors. Named objects.