RE: scrollbar alternative

[Drew Adams]

> BTW there are some minor problems with the code. I will (as usual) try
> to fix them and put the code in the nXhtml repository for the moment.

Yes, like:

1. (eval-when-compile (require 'cl)) ; assert

2. Remove the :background for the left and right portions (or define it as
something different). It is often the case that the inactive mode-line
foreground is the same as the mode-line foreground, which means, e.g., black on
black - no movement shown.

3. Change the default value of `sml-borders' to show the ends, e.g. ("[" . "]").