src: split nfs code info a dedicated module

we quite often need to update NFS code and it's much
simple if a new jar file contains only nfs changes.

There is a change, in pinning via nfs: it will
use DcapProtocolInfo to avoid dependency loop.
Matches current SRM behaviour.

Acked-by: Gerd Behrmann
Target: master
Require-book: no
Require-notes: no