security/libressl: Update to 2.2.5

• Version 2.2.5 addresses CVE-2015-2394
• Refactor regression-test target to TEST_TARGET
• Add LibreSSL < 2.2.5/2.3.1_1 vuxml entry

Reviewed by: koobs (mentor), feld (ports-secteam), delphij (ports-secteam)
Approved by: koobs (mentor), delphij (ports-secteam)
Security: 215e740e-9c56-11e5-90e7-b499baebfeaf
MFH: 2015Q4
Differential Revision: https://reviews.freebsd.org/D4393