Fix NFS & SMB/CIFS Remote collection

BUG: 249760
CCBUG: 232976
CCBUG: 171213
CCBUG: 187692

Using Max's Mass Storage Device code as a guide, this commit returns
network-based collections, shared over NFS & SMB/CIFS to the dynamic
collection architecture.

This should re-validate http://amarok.kde.org/wiki/Dynamic_Collection,
which some people have complained to longer applies.

Test it & break it!