more specifically, every second it will check the memory use;
if the change is more than a megabyte it will update the display
(without some kind of buffer like that, the result will be
different each time it is polled; I tried that an it was
too distracting)
closesracket/drracket#92
in the case that the font size has changed since it was last open
(this doesn't seem to be a problem with only one tab and
may actually be a bug in the way editor canvases with set-line-count
enabled handle font size changes, I'm not sure, but this seems
to fix a fairly annoying behavior I run into)
