Added test - conditional object download

Uses 'If-None-Match' header, should download object only if the local copy is
different.

Change-Id: Ic32e43701538247ef45981826220bca3c1330ce5
Fixes the multi-backend skip bug and the cleanup steps

The multi-backend test class and the tests within should now be
skipped correctly also when running on python 2.6. Also fixes
a cleanup problem occurring in case of error in setUpClass and
speed things up by not creating the 2nd volume/type if backends
have the same name (in which case only part of the tests can be
executed).

Change-Id: Ibeb961ea000bb1d1034f857a64552c7aa75ed4d5
Fixes: bug #1177608
Add python-cinderclient to requirements.txt

The scenario tests manager has an import for cinderclient, however
python-cinderclient was not listed as a requirement. This corrects
the oversight by adding python-cinderclient to requirements.txt.

Change-Id: I92cc4144cc2392391ee80a4f55783acd0f70c483
Multi-server handling in base.py

Moving the logic to handle a list of servers
returned by the create from test_multi_create
into compute/base.py, including test_multiple_create.

Fixes bug #1180823

Change-Id: I2f3ecb44f8a26c4fc912accba2c44707b97ee1e7
Merge "Multi-server handling in base.py"
Merge "Fixes the multi-backend skip bug and the cleanup steps"
Merge "Add python-cinderclient to requirements.txt"
Merge "Added test - conditional object download"