Sync latest context module from oslo-incubator

Change-Id: I635d3e2a24f928015d3511dfcc64b13f9069f892
Inherit Context from oslo

In the long-term, OpenStack projects should use oslo.context as the base
class for their custom contexts. This enables the use of
application-agnostic tools, e.g. global logging configurations.

This patch uses the Context class from oslo-incubator (which will be
soon replaced by oslo.context) as the base class for Sahara Context.
The goal is to be ready for the first oslo.context release.

Change-Id: If7abc705b431aa97cd9d1c59f863d15e6a4fbdef
Partially implements: blueprint app-agnostic-logging-parameters
Don't provide CONF to the AuthProtocol middleware

The conf value that is passed to the AuthProtocol middleware is a
dictionary that is expected to be passed from paste. They are overrides
of oslo.conf not the conf object itself. If we don't pass anything it
will use the standard CONF object.

Closes-Bug: #1398524
Change-Id: Ia53a90f9b632b54a79906f07610c7a1ae1c70218
Merge "Sync latest context module from oslo-incubator"
Merge "Inherit Context from oslo"
Fixed Fake plugin for Fedora image

It is not correct to use '~' inside 'sudo bash' construction. It
depends on system settings and can be changed to '/root'

Change-Id: Ic7c119006b50628a285c7959335ad74594a81c70
Closes-Bug: #1399056
Workflow documentation is now in infra-manual

Replace URLs for workflow documentation to appropriate parts of the
OpenStack Project Infrastructure Manual.

Change-Id: I5ef5385a31f92ab0831e780c96b06da503106f9e
Update conf sample after oslo.messaging release

Change-Id: I5f84247f2afe056bff159baeccdcbbd12ad42545
Merge "Update conf sample after oslo.messaging release"
Updated from global requirements

Change-Id: I0ac05536c5b2beb3eb80b3671ab686edecb3e3e8
Merge "Workflow documentation is now in infra-manual"
Merge "Updated from global requirements"
Merge "Don't provide CONF to the AuthProtocol middleware"