Default security checks for pkgsrc

[Justin C. Sherrill]

/etc/daily and /etc/security in NetBSD now update and check against known
pkgsrc vulnerabilities if there's any packages installed on the system.

http://blog.netbsd.org/tnf/entry/new_package_security_checks

This would be a good idea for DragonFly too - anyone want to tackle it? 
This is probably within my meager skills but not within my meager time
budget.

The diffs, to make it easier:

http://cvsweb.netbsd.org/bsdweb.cgi/src/etc/daily.diff?r1=1.72&r2=1.73&only_with_tag=MAIN&f=h

http://cvsweb.netbsd.org/bsdweb.cgi/src/etc/security.diff?r1=1.106&r2=1.107&only_with_tag=MAIN&f=h