[Rackspace|Compute] updated ready method on Image to raise an exception if an error state occurs. This is similar to the behavior of Server.
Merge pull request #1471 from rackspace/image_ready

[Rackspace|Compute] updated ready method on Image
[rackspace] updated Rackspace to return a list of all services
Merge pull request #1472 from rackspace/fix_rackspace_bin

[rackspace] updated Rackspace to return a list of all services
[ecloud|compute] Fixes ecloud server tests

Fixes regression in #1473, attempting to create an Elcoud service
connection even when tests should not run fails due to missing
credentials.