* moved all services to the separate table, map them to the network_offering+provider.
* added state/securityGroupEnabled properties for the networkOffering
* added ability to list by state/securityGroupEnabled in listNetworkOfferings api command
2) New service: SourceNat
1) Introduce new managers - ProjectManager and DomainManager. Moved all domain related code from AccountManager to DomainManager.
2) Moved some code from ManagementServerImpl to the correct managers.
3) New resource limit for Domain - Project