Add new ec2 volume db API calls

The existing API calls for the EC2 volume ID mappings only returned
the EC2 ID or the UUID, not the full mapping.  We really want APIs
that return the whole mapping for use with a nova object.  This patch
adds those APIs which will be used by the VolumeMapping nova object.

Change-Id: I86361a557254dbddeae2ea49e986add813e5a934
libvirt: Make `fakelibvirt.libvirtError` match

When test code uses `libvirtError`, it may refer to
`libvirt.libvirtError` or `fakelibvirt.libvirtError` depending on
whether `libvirt-python` is installed.

The existing code had incompatible `__init__` singatures between the
two, meaning that a test could pass locally but fail when run on
Jenkins.

The solution is to make `fakelibvirt.libvirtError` match libvirt 1.2.3
exactly.

A convenience function, `make_libvirtError`, is introduced so that
exceptions can still be created in one shot.

Change-Id: I5aaecc57504c4aea3c049610ef188978c25cfdc4
Closes-Bug: 1305186
Don't translate debug level logs in nova.volume

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: Ib529afea4d1696d8905e2d533803562130950d83
Don't translate debug level logs in nova.api

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: Ifb04bf41a47f485e8c668632d3a6ac51e02a16f8
Don't translate debug level logs in nova.cells

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: Idb346d04f24cbbc19b6e41af6e4782ac1c49d3b8
Don't translate debug level logs in nova.conductor

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: Id270b6c7e020679c3e2e3931300e82ea3489e942
Merge "Don't translate debug level logs in nova.volume"
Merge "Don't translate debug level logs in nova.api"
Merge "Don't translate debug level logs in nova.cells"
Merge "Don't translate debug level logs in nova.conductor"
Merge "Add new ec2 volume db API calls"
Merge "libvirt: Make `fakelibvirt.libvirtError` match"