Fixes the issue reported by @fetzerch that as a result of #1719 the watched status and resume position supplied by the PVR client are overwritten with the values read from the library. If the backend is also used without XBMC, those values can differ.
With this PR the respective values of the PVR client (if available/supported) take precedence over those from the library.
[pvr] Use play count and resume point information from the PVR client…
… if available.