Motivation:
Java9 module subsystem doesn't allow different one package to exists
in two jars files. As org.dcache.utils is too generic and exists in
other dcache components as well, we have to avoid it's usage.

Modification:
rename org.dcache.utils package to org.dcache.nfs.util

Result:
initial step in a direction to provide Java9 compatible modules

Acked-by: Lea Morschel
Target: master