mdsaltrace utility for debugging

Moved back to controller per decision from kernel meeting
a few weeks ago.

TracingBroker logs 'write' operations
and listener registrations to the md-sal. It logs the instance
identifier path, the objects themselves, as well as the stack trace of
the call invoking the registration or write operation. It works by
operating as a "bump on the stack" between the application and actual
DataBroker, intercepting write and registration calls and writing to the
log.`

+ karaf4

Change-Id: Ie7d27901429f6e7bcac7ff62e49e4e3115f5915f
Signed-off-by: Josh <jhershbe@redhat.com>
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>