Renaming and huge restructuring of service endpoints and assistants

The rename gets rid of the awkward ".service.contacts.carddav" and now it's just called "org.webosports.cdav". It's short and includes caldav and carddav at the same time. The UI reports it as c+dav, recommended by morphis. But I did not want to risk having a + in the config files (and filenames). I'm pretty sure something will fail about that. ;)

Additionally I reworked the service endpoints and service assistants. There are now dedicated endpoints for calendar and contacts which solves some issues with account creation and deletion and did the trick with disabling / enabling single capabilities. We got that more or less for free. 
Only now there are specialisations of the assistants for the capabilities and we need to maintain two kinds objects which the serviceassistant has to select and deliver to the SyncClient (i.e. its super class).

If old installations are around, this will be installed next to them, because all of the names and kinds have changed. So old account have to be deleted and the old software can be uninstalled. 

Also I introduced some kind of change log and bumped the version a bit, because I try to get some testing going. 

Open-WebOS-DCO-1.0-Signed-Off-By: Achim Königs <garfonso@mobo.info>