Fix AutoScaling use of LoadBalancing and CloudWatch services - EUCA-8853

AutoScaling now sends service messages to the (user facing) service
components for LoadBalancing and CloudWatch services rather than the
backend components.

EUCA-8853
Merge remote-tracking branch 'origin/dev/sjones/EUCA-8853' into testing
Add EC2 error for invalid image / instance-type combination - EUCA-8831

Selection of an instance type that is too small for the specified image
now results in an InvalidParameterCombination client error.

EUCA-8831
Fix snapshot download from objectstorage for enabling snapshot sharing across
multicluster environments with each cluster tied to a different storage backend

Fix reporting event fired on snapshot creation
Modify property errors are now propagated to client - EUCA-8806

The euca-modify-property command will now fail with an error when a
property change fails.

EUCA-8806
Network configuration property validation improvements - EUCA-8806

EUCA-8806