RAND_load_file(..., -1) now means "read the complete file";

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).