Global data layer to avoid multiple data handling in client applications

[slawor]

The server provides multiple services to get data like products or resources. There can be multiple modules which needs the same data but every module must handle it itself. It would be usefull to have a kind of data layer which can be used from every client module to get the needed data. The data layer can connect to all provided services and collect all provided data and keep it up to date. There is also the possibility to inform all modules about a disconnect.