simplified a lot of the upscale code
simplified a lot of the upscale code

* Before there were a lot of checks for the upscale,
this is from a time when it was optional.
It is no longer optional, and so this is removed.

* The upscale field in the CanvasManager was
renamed to $upscale, to reflect that it is a jquery
object.

* the upscale field was added to the CanvasManager
for accessing the internal upscale canvas.

star090807/SkyBrush,star090807/SkyBrush