Return to skipping filters when using force_hosts.

The folsom behavior was to skip filtering when using force_hosts.
This is useful for administrative tools. For example, one can verify
a disabled node by launching instances on it even though the scheduler
will ignore it for normal requests. This behavior was accidentally
changed in commit 0d9ce8319d75bfbd69fe4e0759aeed38e6054e56

Change-Id: Ib529cf8eccc4d8abe67873cfc0467f6db9d4b522
hypervisor-supplied-nics support in PowerVM

PowerVM does not allow MAC addresses to be directly set on LPARs.
Instead, use the hypervisor-supplied-nics feature to generate MAC
addresses we can ensure are provisioned correctly.

blueprint powervm-compute-resize-migration

Change-Id: Idad7f03d9fd61970912ec1a6978fc0af56309df4
Ban database access in nova-compute

This adds a wedge between nova-compute and the database implementation
to specifically catch, log, and deny accesses. Theoretically, this
should not be needed as a production environment would not even have
the compute nodes configured to talk to the database. However, testing
and upgraded environments may retain database access and thus avoid
hitting real issues that can be fixed up prior to release. Putting
this into the tree now will help ensure we have a consistent error
scenario for test setups prior to release.

Note that if nova is configured to use a local conductor, we do not
insert the wedge, which provides an easy out for anyone needing to
get a production system past a missed database access.

Related to bp no-db-compute.

Based on Russell's original tracer hack:

   I328fa92d5bfdadd5022f5c7efe981396d8ae7962

Change-Id: I478230220633e0d2ff94b6a4d756e07eab8517d7
Fix lazy load 'system_metadata' failed problem.

When using lazy load of SQLAlchemy, parent instance may have
a problem not bouding to a session object and fail the lazy loading
system_metadata.
Using joinedload to eagly load the system_metadata in
_instance_get_all_query to fix the problem.

Fixes: bug 1117232
Change-Id: Id24ca534f6eb57167aee22aca12c1274c90baf3c
Support hypervisor supplied macs in nova-network

When hypervisors supply a set of MAC addresses for instances, have
nova-network use the supplied values when creating VIFs.

This function is required for the PowerVM driver to be properly
supported.

Change-Id: I922797af6b2b829561f61095bef2098c2d31cde5
Access DB as dict not as attributes part 5

Partially implements bp db-api-cleanup
Change-Id: Id34c20701ae0cae503c2218c9a6008d5e0bb0e76
Merge "hypervisor-supplied-nics support in PowerVM"
Merge "Ban database access in nova-compute"
Merge "Support hypervisor supplied macs in nova-network"
Merge "Return to skipping filters when using force_hosts."
Merge "Fix lazy load 'system_metadata' failed problem."
Merge "Access DB as dict not as attributes part 5"