LoadBalancing service support for resources in IAM policy - EUCA-10052

IAM policies for ELB can now specify load balancer ARNs for resource
specific permissions.

ARN parsing is modularized to allow services to provide their own ARN
representation and parser.

EUCA-10052
Update IAM policy unit tests - EUCA-10052
Merge remote-tracking branch 'origin/dev/sjones/EUCA-10052' into testing
Move imaging query binding unit test - EUCA-10002