security/libressl: Update to 2.2.1

• Minor update from OpenBSD LibreSSL-portable
• Bumps all SHLIB versions
• Bumps OPENSSL_SHLIBVER in bsd.openssl.mk
• Adds UPDATING entry for SHLIB version bump
• MFH as 2.2.0 already closes several vulns

Changes:

ftp://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.2.1-relnotes.txt

Differential revision: https://reviews.freebsd.org/D2963
Reviewed by: vsevolod (maintainer/mentor), koobs (mentor)
Approved by: vsevolod (maintainer/mentor), koobs (mentor)
MFH: 2015Q3