user-space XO hardware detection

[Albert Cahalan]

It's getting more and more important to be able to detect XO hardware
from userspace. One can no longer assume that Sugar implies XO because
Sugar runs elsewhere and because non-Sugar is getting common on the XO.
Considering the 1.5 hardware, assuming that Geode implies XO is not
going to be reasonable either.

I suppose the real needs are:

1. detect that the screen has XO-like blur
2. detect that the keyboard has XO-style keys
2a. detect that there is a multiply/divide key

If possible I'd like to do this as a regular user, without X server
help, in both Sugar and non-Sugar situations, despite any Bitfrost.