[Nauty] Nauty distribution minor change

[Brendan McKay]

Beta 2 of version 2.2 of the nauty package is online.  There is
no change to the main nauty files, but the random number generator
in rng.c has been corrected after Don Knuth found an error.
You have not been bitten by this error unless you used rng.c
in your own programs and forgot to initialize with ran_start()
or ran_init().  I'd advise you to upgrade if you rely on the
"s" command in dreadnaut or the genrang program, even though
I don't think they were affected by the bug.

ALSO: I wonder if anyone got version 2.2 running on a PC.
If so please be in touch.

Brendan.