Add missing translation support

A log message was missing the translation support.

Change-Id: Ib4320a7fe1609c6cf33835f9873a2ddbda211c8c
V2 Pause: treat case when driver does not implement the operation

Some virt drivers may not support this operation.

Same change will be added to V3 when https://review.openstack.org/#/c/58432
is merged.

Change-Id: I7763f462dd8f61c29c79038d881dc015482a9b5c
Emit message which merged user-supplied argument in log_handler

Sync from Oslo, change-id: I91289cc4a60f5dab89bca852e6f52b4b83831e47

When using PublishErrorsHandler, it will missing user-supplied arguments.
For example, do LOG.info("blabla %s", "foo"), the payload only contains
"blabla %s", but we expect it like "blabla foo". This patch fix it.

Change-Id: I375b0d83783b1866d3bf30ff3ade27e746bb856b
Closes-bug: #1278291
Make webob.exc.HTTPForbidden return correct message

Currently HTTPForbidden is using wrong parameter 'detail'
somewhere, while the correct parameter should be 'explanation'.
This patch fixes this bug.

Change-Id: I69bc3249f88e9cbf9add954571c21b07cf58f7c6
Closes-Bug: #1283872
Update ubuntu dev env instructions

I just set up an environment to run unit tests on Ubuntu and had to install a
couple of additional packages to make it work.  Update the instructions to
reflect that.

Change-Id: I2ceb1b130111991fa1b34b4636b8ece115e54084
Merge "V2 Pause: treat case when driver does not implement the operation"
Merge "Add missing translation support"
Merge "Update ubuntu dev env instructions"
Merge "Make webob.exc.HTTPForbidden return correct message"
Merge "Emit message which merged user-supplied argument in log_handler"