Now v2 API uses code from v3. It's confusing and logically incorrect.
This patch makes v3 API as an extended version of v2.

The next patches related to this bug duplicated code between v1 and v2,
v2 and v3 will be removed.

Change-Id: I90a2b713556e91db69270a03ef6b798e08f93f90
Partial-Bug: #1643584

The unicode_key_value_to_string() function is designed to remove
extra 'u' in cinderclient cli output.
However this patch[1] bring the extra 'u' back.
Let's remove the extra 'u' again.

Closes-bug: #1615921
Closes-bug: #1606904

[1] https://review.openstack.org/#/c/342734/
Change-Id: I26f0ad7149f57e935953c2398ba90b7b3585e201

WebOb change https://github.com/Pylons/webob/pull/230 changed
the way in which the error response body is formatted such that
it's no longer a nested dict. So we have to handle both the
old convention of an error message key to the response body error
dict and the new way with just the error body dict.

This was reported upstream:

https://github.com/Pylons/webob/issues/235

But given this was apparently implemented as a long-overdue change
in WebOb the behavior is not likely to change.Handle error response for
webob>=1.6.0

Change-Id: I7d589415aa024588faf77c8234ac026110f6c3cd
Closes-Bug: #1559072

A StreamHandler was being setup that dumped logs to the console
regardless of the user's wishes. This removes that StreamHandler
setup so that the user can control the logging themselves.

Change-Id: I02756539a7c094153b9ec29a0ff2fecaabd44f71
Closes-Bug: #1647846

As mentioned in [1], we should avoid using six.iteritems(iter) to
achieve iterators. We can use iter.items() instead, as it will
return iterators in PY3 as well.

[1] http://lists.openstack.org/pipermail/openstack-dev/2015-June/066391.html

Change-Id: Ic41abf2ca6ec3ecb651b980091b52d0a185c9089