debian/control: Recommend lsb-release.

In the past few days several people on IRC have had issues with Facter
not filling in ``lsbdistcodename`` which can usually be traced back to one
of the lsb-* packages missing on Debian.

By depending on ``lsb-core`` we ensure that core LSB functionality is there.
This package additionally depends on ``lsb-base``, ``lsb-release`` and
``lsb-security`` ensuring everything is in place for Facter.