Added the entire epoch as a period named '__EPOCH__'

Stopped collecting cpu_util, network.(incoming,outgoing).bytes.rate
meters for periods, and collect 'instance' meters per period (these just
show how many instances were on each hypervisor during the period).

Stopped collecting port.(delete,create,update) events -- far too many
and they essentially relate n-to-1 with VMs (where n is usually 1, 1
port per VM).

Handle some weird inconsistencies in resource metadata (it seemed that
for some VMs, some of the metadata wasn't set and thus we were not
including said VMs in the primary VM info dict -- and this seemed to
cause problems for the javascript graph stuff).

Also, if a resource/meter value isn't associated with a hostname, use
the 'UNKNOWN' hostname instead of None/null.  For whatever reason, this
occurs with image.update now; funny.

Get rid of the __FLATTEN__ stuff; that was just a lingering turd.