CLOUDSTACK-1117 [EC2 Query API] DescribeImageAttribute fails

EC2DescribeImageAttribute fails with 'Unsupported - only description supported' error. And this is observed for both the supported attributes 'Description' and 'LaunchPermission'
[EC2 Query API] DescribeAvailabilityZones doesn't have any filter support.

CLOUDSTACK-1118

Support will be available for filters - zone-name and message
CLOUDSTACK-1119 [EC2 Query API] Add filter support for DecsribeAddresses

EC2DescribeAddresses doesn't have filter support.
Support will be available for filters -> instance-id and public-ip