Reduced LiveQuery update latency from 500ms to 200ms
Reduced LiveQuery update latency from 500ms to 200ms

Fixes #1046

couchbase/couchbase-lite-ios,brendand/couchbase-lite-ios,couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,couchbase/couchbase-lite-ios,brendand/couchbase-lite-ios,couchbase/couchbase-lite-ios,brendand/couchbase-lite-ios,couchbase/couchbase-lite-ios,brendand/couchbase-lite-ios,couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,brendand/couchbase-lite-ios