avoid use of prohibited MD5 algorithm.

instead of local time.

we were mislead by _MSC_VER macro, which is defined by *all* Windows
Microsoft compilers.

compilers, e.g. DEC C.

_stricmp() on that platform, use the appropriate header file for it,
<string.h>.
o_str.h: we only want to get size_t, which is defined in <stddef.h>.

Philippe Bougeret <philippe.bougeret@freesbee.fr> notified us about Windows
not having a <strings.h>

Add a note as to how these functions do not always return the key size, and
how one can deal with that.

PR: 907

PR: 499

there's no need for a larger BUFSIZE any more...

PR: 904

PR: 904

PR: 905

cipher ASN1 parameters and the cipher doesn't support it.

PR: 900

Makefiles where this was fixed by commenting away code, change it to
check for an empty EXHEADER instead, so we have less hassle in a
future where EXHEADER changes.

PR: 900

*cnids.

essentially a copy of crypto-lib.com, with just a few edits.