The latest beta, when I ctrl-c the render, and then retry it, it doesn't seem to
continue the render, rather starts the new one.
I'm testing this with newdiffract.pov from the 'advanced' scenes.
povray +i newdiffract.pov +w1280 +h1024
After rendering around 50% of the image I hit ctrl-c. Then in hit 'up-arrow',
hit 'enter', and render wont continue, it starts over.
