check_packages should find security updates on the official security mirror too

[1] says one should use the following line to get security updates for Debian:
  deb http://security.debian.org/ wheezy/updates main contrib non-free
this produces the following `apt-cache policy <pkg>` output:
  500 http://security.debian.org/ wheezy/updates/main amd64 Packages
which does not match the current regex, as this looks for `debian-security`
(which is only present on "regular" Debian mirrors).

The new regex matches security.debian.org and also the (obsolete)
security.eu.debian.org and security.us.debian.org names.

[1] http://www.debian.org/security/
Merge pull request #15 from evgeni/master

check_packages should find security updates on the official security mirror too
Add check_checksums nagios plugin.
Updating check_raid.
Updating check_ssl_cert to 1.14.6
Updating check_hpasm to 4.6.3.2
Updating check_multipath to 0.1.9
Updating check_whois to 1.13
Refreshing patches.
Auto update of debian/control
Auto update of debian/copyright
Updating changelog.
Fix src link for check_hpasm
check_libs: ignore /var/lib/postgresql/

it contains only data and produces false-positives like this:
adding postgres(5733) because of [/var/lib/postgresql/9.2/main/pg_xlog/000000010000002D000000F9 (deleted)]:
check_libs: ignore /var/log/
Support pre-Wheezy versions of coretutils in check_checksums.
Updating changelog.
Update release date in changelog (gah!).
Merge pull request #16 from evgeni/master

check_libs: ignore /var/lib/postgresql/ and /var/log/
Updating changelog again.