Monday morning Management Libraries fixes

- Fixes windowsazure/azure-sdk-for-net-pr#295 RT fix - ComputeClient.VirtualMachineDisks.CreateDisk() should handle null OperatingSystemType input
- SQL: Dacs.GetStatus doesn't take fully qualified server name in query string
- SQL: Dacs.GetStatus not parsing response
- SQL: Databases.Get not parsing response