See merge request nexedi/slapos.core!434

Until now, the broadcast address was used for the tun interface instead
of the first address of the range.

See merge request !436

See merge request nexedi/slapos.core!435

  We do want to ignore payments that occur after the at_date.

  We want to know if at a certain date, there still unpayed documents older them that date, if the document is payed after, (and grouped) we unconsider it.