JDownloader

Add Views Support

At the moment clients work directly on backend and therefore have to implement all sorting/filtering/views.
Adding Views will allow a client to use all methods from JDownloader and also increase speed/reduce latency/traffic.

Client requests a new view and receives an ID.
Then it can set filters, enable/disable views, sort. All will be done on JDownloader side.
Client no longer works directly on backend, it will work on the view and receive updates/events/data from the view only.

TODO:
-new api
-eventsystem for views
-virtual view management (eg virtual tables)