Use BoolVar for isWatcher -client and -watcher flags.

Change-Id: Ia76b216a1a1f5328b578919f6985623e80ff9354
Reviewed-on: http://review.couchbase.org/43810
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>