#2 Canvas should resize according to window (Burana #3198)

[Mikko M�kel�]

The green-blue area (Canvas?), used for holding the
moveable components (JARs, packages, classes) of the
visualizator, should resize automatically according to
the window size.

Now the size is dependent on zoom level, and this will
cause a huge margins which are totally useless.

How-To-Repeat: Visualize, zoom and resize the window.

Suggested-Fix:
The Canvas size propably has something to do with zoom
implementation, so it could be hard to fix without
re-writing the whole thing.