ENGINE code does not return a default, set an error.

sure they are available in opensslconf.h, by giving them names starting
with "OPENSSL_" to avoid conflicts with other packages and by making
sure e_os2.h will cover all platform-specific cases together with
opensslconf.h.

I've checked fairly well that nothing breaks with this (apart from
external software that will adapt if they have used something like
NO_KRB5), but I can't guarantee it completely, so a review of this
change would be a good thing.

strings, it's just the default because it's usually ok.

returns int (1 = ok, 0 = not seeded). New function RAND_add() is the
same as RAND_seed() but takes an estimate of the entropy as an additional
argument.

codebase apparently was inconsistent.  And crypto/Makefile.ssl
*does* need an ERRC ..
Submitted by:
Reviewed by:
PR:

script, translates function codes better and doesn't need the K&R function
prototypes to work (NB. the K&R prototypes can't be wiped just yet: they are
still needed by the DEF generator...). I also ran the script with the -rewrite
option to update all the header and source files.

Submitted by:
Reviewed by:
PR:

(Pointed out by Carlos Amengual).