random(4) plugin infrastructure for mulitple RNG in a modular fashion

[Simon J. Gerraty]

>> Our approach is mechanism over policy.  That is, give the user the
>> choice of if their HW should be used directly or fed into the SW PRNG.
>
>I don't see a problem with that either, as long as there are no nasty
>surprises like the possibility of getting no RNG at all, and not being
>in a position to notice.

If there are bread crumbs to show whether an RNG is present or not in
the output from config, it should be feasible to fail the build
which as others have noted would be a "good thing"[TM] vs producing a
toxic kernel.