CLOUDSTACK-4190:[Object_store_refactor] volume should be deleted from
staging storage after successfule volume migration .
CLOUDSTACK-4190: Add endpoint selector implementation for ImageCache
data store and also delete object from staging area for volume copy from
primary to secondary or vice versa.
CLOUDSTACK-4069: listNetworkOfferings API has been changed to not return system-owned network offerings to regular user(domain user). Therefore, change UI to determine whether a network is EIP/ELB upon listNetworks API response instead of listNetworkOfferings API response.
CLOUDSTACK-856. DOC. Document CPU and RAM overcommit functionality.