PMS handling re-thought - collect all PMS/Sections on main Library page

This is one heck of a "tester's commit".
Known Issues:
- Settings->PMS has pretty much no effect any more
- Search only works on one PMS
- Channels are pulled only from one PMS
PS: tomer asked for this about 5 month ago… "the difficult is done at
once; the impossible takes a little longer".