MEM: VirtualPorts are replaced with FSTranslatingProxys

This patch introduces the FSTranslatingProxy instances replacing the
VirtualPorts. This requires small chagnes to many files.  Some
functionality (object loading) in constructors of System and derived
objects have been moved to the initState methods instead. This method
is called after the interconnections has been established, therefore
the PortProxies are functioning.

util/regress passing all ignoring failing eio and t1000