🚀 go-pugleaf

Hi, all:

	Just want to add that this version of "scrollable" will only
work with 3.1b, since 3.1a seems to have a weird problem with redrawing.

	So, the base call convention is:

	Scrollable* s = new Scrollable(Glyph*, Coord, Coord);

	However, the Glyph* must be a Instance of Page (other wise why
would you want to scroll it? :)).

	I know, I know, I can probably make it better if I spend a few
more days on it. But my main project is due soon. :(

	-- Chen Wang