Implemented support for Merlin 2/Livestatus

In Merlin 2, the MySQL status tables are disabled by default for
performance reasons. In Monitor 6.0, we instead use Livestatus to get
status data.

This patch (based on a patch by Misiu Pajor <misiu.pajor@op5.com>)
implements talking to Livestatus to get status data instead of talking
to MySQL.
Changed font size to less ridiculous value

24px was a little ridiculous, so we scale down to the slightly more
reasonable 18px.
Clarified code ancestry

Some socket code was borrowed from the mklivestatus-slave project,
because I'm lazy. Credit where credit is due.