I noticed in OpenStack production we don't seem to be getting all the
stats from dib, particularly from our very remote builder. This is
likely because there is some packet loss quickly blasting out small
UDP packets with the stats. A pipeline bundles the stats together
into the largest size packets it can (this has been a problem before;
see I3f68450c7164d1cf0f1f57f9a31e5dca2f72bc43).
Add some additional checks for the size stats which did not seem to be
covered by existing testing.
I also noticed that the documentation had an extra ".builder." in the
key which isn't actually there in the stats output.
Change-Id: Ib744f19385906d1e72231958d11c98f15b72d6bd
c68dbb9636