[HTTPS-Everywhere] HTTPS Everywhere not working on Firefox 4.0b3

[ne6 at parsoma.net]

A couple of other people have reported this on this mailing list
without receiving replies, so I'll add my report: FF 4.0b3 (and
FF4.0b2 when I ran that) causes this extension not to function, its
settings window not to show available redirects, and all three
buttons on the bottom to do nothing when pressed.

To answer one of the objections to a previous report of this
behavior, I verified this against a new, pristine profile lacking
any other installed extensions.