enables the build against LibreSSL (OpenSSL head has also removed this
header)
- Simplify WRKSRC and move it where it normally belongs in Makefile
- Remove no longer required "/LIBS=/s|-lpthread|-pthread|" gimmick, and
bring Makefile header under standard form
- Provide a better port description while I'm here
PR: 198984
Submitted by: Bernard Spil
