[rackspace] added transaction id to monitoring exceptions; passing service into slurp for compute, databases, dns and load balancers
[aws|iam] Make mock EntityAlreadyExists message match reality.
[openstack|image] strip unused headers in #update_image

* update tests to pass both live and mocked
Merge pull request #2073 from burns/openstack_image_tests

[openstack|image] strip unused headers in #update_image
Merge pull request #2072 from rackspace/trans_id2

[rackspace] added transaction id to monitoring exceptions
[rackspace] fixing broken tests
Merge pull request #2074 from rackspace/exception_fix

[rackspace] fixing broken tests