Port certificates API to v3 Part 2

This patch contains the changes required to adapt the certificates
extension and the corresponding unittests to the v3 framework

Partially implements blueprint nova-v3-api

Change-Id: If4fe7e8524ba0181b50722281f594e0a80cd49ed
Cleanup certificate API extension

Fixes a couple of minor issues with the v2 and v3 versions
of the certificate API extension identified during the
v2->v3 port
* Removes unused CertificatesTemplate class
* Corrects doc strings for a couple of methods

Change-Id: If022d2393ceab5ce7e6311c92a6f52b6325039bc
Remove locals() from nova/virt/libvirt package

fixes bug 1171936

Change-Id: I81198d6bc74991b184b3de2f7977ff3a9a12ac28
Fix quota logging on exceptions

When exceptions committing or rolling back quota reservations occurs, we
log the failure.  However, the code also falls through to log a
succesful commit/rollback.  This adds the missing returns.

Change-Id: Ieccb4071c64dde740ec95a783533a8a3a1850481
Port missing bits from httplib2 to requests

This allows to drop the dependency on httplib2 altogether.

Change-Id: I18571e29d9f0d6527a93ed18becee9148e64e574
Fix KeyError exception when scheduling to child cell.

Fix typo 'security_group' and update related unit tests.

Fix bug #1193233

Change-Id: I6d92759b0d7e2ce81c2065a4eada35c559ccbcd7
Merge "Port certificates API to v3 Part 2"
Merge "Cleanup certificate API extension"
Merge "Remove locals() from nova/virt/libvirt package"
Fix sys_meta access in prep for instance object

Fix various places that access instance['system_metadata'] as if it's a
list of sqlalchemy models.  A helper util method was created in a
previous patch set in nova/utils... so this patch converts things to
use it.

Left one use in _init_instance() in compute/manager.py because it's
being addressed with a different patch set.

Related to blueprint unified-object-model

Change-Id: I876a6c57f64d61d64069c884bf0414c3596e1aa0
Merge "Fix quota logging on exceptions"
Merge "Fix KeyError exception when scheduling to child cell."
Merge "Port missing bits from httplib2 to requests"
Merge "Fix sys_meta access in prep for instance object"