[desktop-lite] Use resizeSession

[davetapley]

I assume that if we set resizeSession on noVNC, then it would tell Fluxbox to change its resolution to match the window size?

Currently it's defaults to 1920x1080 and so windows can appear off screen, although it is possible to manually change it to fit in the window.

[davetapley]

Or optionally let us pass a resolution in as an option and then:

echo 'xrandr --output VNC-0 --mode 1024x768' >> ~/.fluxbox/startup