Replicator: avoid stagnant remote _changes progress
Replicator: avoid stagnant remote _changes progress

If there's no progress with a remote _changes stream, retry
up to 10 times with an increasing pause period before each
retry attempt. If there's progress retry immediately - any
other connection (worker connections) that fails 10 times will
end up aborting the replication process.




git-svn-id: c1f8a8ec0b3bb2e99ab3413722f81f687760e79c@1102699 13f79535-47bb-0310-9956-ffa450edef68

fkaempfer/couchdb,fkaempfer/couchdb,alanning/couchdb-couch,fkaempfer/couchdb,KlausTrainer/couchdb-couch,KlausTrainer/couchdb-couch,apache/couchdb-couch,cloudant/couchdb-couch,cloudant/couchdb-couch,smithsz/couchdb-couch,ngpestelos/couchdb-couch,alanning/couchdb-couch,apache/couchdb-couch,apache/couchdb-couch,ngpestelos/couchdb-couch,smithsz/couchdb-couch,fkaempfer/couchdb,cloudant/couchdb-couch,KlausTrainer/couchdb-couch,alanning/couchdb-couch,smithsz/couchdb-couch,fkaempfer/couchdb,ngpestelos/couchdb-couch,fkaempfer/couchdb