this is what we now use to read $RANDFILE / $HOME/.rnd.
(Previously, after 'cat'ting lots of stuff into .rnd
only the first MB would be looked at.)

Bugfix for apps/enc.c: Continue if RAND_pseudo_bytes returns 0
(only -1 is an error).

RSA structures. Other structures behave in
a similar way.

Slightly clarify the RAND_... documentation.

Add a note about the padding functions.