MB-10073: implemented UI/js for xdcr pause-resume

This is based on prior ui work by Pavel Blagodov submitted here:
http://review.couchbase.org/33439

Change-Id: Ifa5fac1748746d5459bf4d1636f6efea9d18526a
Reviewed-on: http://review.couchbase.org/33711
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>