Only initialize the glance_http if service is enabled

This commit just adds a check to see if glance is set as enabled in
the config file before initializing the glance http client. Previously
regardless of whether glance was enabled or not glance_http would
auth against keystone.

Closes-Bug: #1214774
Change-Id: I07127c21d55d58fdb294468a0b74ce2bc54d8719
port instance_usage_audit tests into nova v3 part1

This changeset only copies the v2 files into the appropriate v3
directories unchanged. This is being tried in order to make
reviewing of the porting easier as gerrit will display only what
is actually changed for v3 rather than entirely new files.

Partially implements blueprint nova-v3-api-tests

Change-Id: I7d1e6437cca25ab7da4e1d74f617e51f17951ba6
Add unit tests for rest_client

This commit adds the first unit tests for the rest client. This is just
the first basic set of tests which were written to mostly verify some
common fake objects that will be useful moving forward. The intent is
for more advanced to be built off of this.

Partially implements bp unit-tests

Change-Id: I19173523ceec3c4fce62f9a3ab61cc9ee23c1801
Remove unnecessary spaces from messages

If a timeout happens in _status_timeout(), exception message includes
many spaces like the following:

Timed out waiting for thing <<id>>                       to become ..

This patch removes them for log readability.

Change-Id: I5cfea5b447bcdd280b25878e95fa938229038d25
Refactor cross_tenant_connectivity for tenant isolation

Closes-Bug: #1262613

Fetch tenant creds from isolated_creds if needed to allow for parallel
execution

Change-Id: I507899fd0b4a0bec3312bfb394363d9591b38282
Merge "Only initialize the glance_http if service is enabled"
Merge "Refactor cross_tenant_connectivity for tenant isolation"
Merge "port instance_usage_audit tests into nova v3 part1"
Merge "Remove unnecessary spaces from messages"
Merge "Add unit tests for rest_client"