Improve display of QueryParams in ec2QueryDebug.
Add rdsQueryDebug.
Add DescribeDBSnapshots.
Add CreateDBSnapshot.
Add DeleteDBSnapshot.
Add a test case for DescribeDBInstances.
Add DBSnapshot module into cabal file.
Add a test case for DescribeDBSnapshot.
Add a test case for {Create,Delete}DBSnapshot.
Fix #103: Change type of privateIpAddress and sourceDestCheck in InstanceNetworkInterface.