Transform the supervisor_notify() and related functions into
the "supervisor" class and place this class implementation in
a separate .cc file.
This is going to fix the compilation breakage of tests introduced
by a
commit 8014adc2a1
init: serialize the creation of system_traces KS objects
Signed-off-by: Vlad Zolotarov <vladz@scylladb.com>
Message-Id: <1483663955-20096-1-git-send-email-vladz@scylladb.com>
