add periodic state check for leader state

Under certain rare conditions the Leader can be in a corrupted state
which takes some time to resolve. A periodic state check has been
added for the following:

* if the elected leader is unknown, a scout is started
* if the elected leader is remote, but there is no leader watcher, a
leader watcher is started
This is probably best as startScout() ... just because we don't know who the right leader is, doesn't mean there isn't one.