Ensure we can cancel a fullsync and restart.
add stop command and read assertion to repl_cancel_fullsync
Make repl_cancel_fullsync more robust

 * add repl_util:wait_until_fullsync_started/1
 * add repl_util:wait_until_fullsync_stopped/1
 * remove timeouts and use above calls to confirm our test is in the
   right state
Verify that after stopping, no sources running.
Ensure keylist pids are stopped when fs cancelled

When fullsync is cancelled, we want to make sure that the keylist pids
it was using actually go away. Add that code to repl_cancel_fullsync.
Merge pull request #618 from basho/feature/csm/cancel-fullsync

Ensure we can cancel a fullsync and restart.