Server/op5Monitor: Print duration in human-readable format

Since we get duration as "timestamp since last change", we need
to massage it a bit so humans can read it.

This patch modifies the unix timestamp to the format of
  Aw Bd Ch Dm Es
where A=weeks, B=days(24 hours, really), C=hours, D=minutes and
E=seconds.

Signed-off-by: Andreas Ericsson <ae@op5.se>
Server/op5Monitor: Submit commands via API

We don't support the CGI's anymore, so we have to submit commands
via our API. Fortunately, that's quite pleasant, so we end up
removing more code than we add, which is a Good Thing(tm).

Signed-off-by: Andreas Ericsson <ae@op5.se>