Move DVR to the idnode system

It affects

* DVR log tables (upcoming, finished, failed)
* DVR autorec
* DVR config profiles

The old configuration and log entries _should be_ converted automagically...

<B>NOTE: BACKUP YOUR CONFIGURATION DIRECTORY BEFORE USE SO YOU CAN REVERT!!!</B>

EDIT: Sep 4, things are going to be useable. Improved javascript. More testing required.
EDIT: Sep 5, added the automatic config backup after any tvh upgrade (to <CFG>/backup directory).