Image setDelay bugfix

[ascholerChemeketa]

Existing image code has an assumption that no more than 2 lines will need to be redrawn.
If updateInterval > 2 * width that will not be the case and the image ends up with banding.
This allows for an arbitrary number of lines to be redrawn at each repaint.

It also removes what I believe to be an extraneous condition:
else if (self.lasty + self.updateInterval >= self.height)
From what I can see, either we are in a row and going to stay in that row (the else), or we are going to finish a row and possibly wrap to a new row (first if).

[bnmnetp]

I don't remember my logic from way back then. My guess is I was trying to minimize the number of pixels I was pushing around. But I wonder if today it would not be simpler to just redraw the image from the beginning to the current location at each interval?

But, if this works, then I'm also fine with just merging it too.

[ascholerChemeketa]

There does not appear to be much speed up to the partial redraw.

Latest commit just redraws the whole image - doesn't even bother to only redraw up to current location. It seems to run at about the same speed.

If you want simple code path, use the last commit.
If you want to keep the potential optimization, use the previous one.

[bnmnetp]

I think at this point the simple codepath is better.... Nearly a decade of Moore's law and better javascript engines make things easier.

[bnmnetp]

I'll try to get this merged later today and get a new release done before rebuilding tomorrow.