Plotchart: New functionality

[Arjen Markus]

Hi all,

I have been adding quite a bit of functionality to Plotchart. It is
all in CVS if you want to try it yourself.

Not everything is ready, but I would like to ask you to try it out and
let me know about problems.

New features:

- 3D bars and other "business graphics"
- Legends and textual annotations
- Vector plots
- Gradient and image background
- Data represented as dots of different size and colour

Regards,

Arjen