Add AggregateRamFilter

Implements blueprint per-aggregate-resource-ratio

* AggregateRamFilter to support per-aggregate ram_allocation_ratio
* Falls back to global setting if per-aggregate value not found

DocImpact

Change-Id: I93e069f0ac3f595d9a2a17119274c7bfbe8fca31
Add AggregateCoreFilter

Implements blueprint per-aggregate-resource-ratio

* AggregateCoreFilter to support per-aggregate cpu_allocation_ratio
* Falls back to global setting if per-aggregate value not found

DocImpact

Change-Id: I9230f46e2490226f3c50d616aa173d4722095087
Port images functionality to v3 API Part 1

This changeset only copies the v2 implementation file into the
appropriate v3 directory unchanged. The copy as-is will not be
loaded by either the v2 or v3 extension loaders. The second
changeset will then make the changes required for it to work as a
v3 extension.

This is being done in order to make reviewing of extension porting
easier as gerrit will display only what is actually changed for v3
rather than entirely new files

Note that this functionality will be moved from core to an
extension.  Consensus appears to be that we continue to need this
functionality for v3 because some deployers disable the public
image endpoint due security concerns and whether this will be
fixed in glance for Havana. Deployers can disable this extension
if they do not want it.

Partially implements nova-v3-api

Change-Id: I02b32b40b14a5593bf254ad9e6a78c14cb15ced5
Merge "Add AggregateCoreFilter"
Merge "Add AggregateRamFilter"
Merge "Port images functionality to v3 API Part 1"
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp