COUCHDB-810: Adds port to replication checkpoints.
COUCHDB-810: Adds port to replication checkpoints.

New replication checkpoints now include the port number, which allows for efficient replication between multiple couchdb instances running on the same machine.

Old replication checkpoints are recognized (Full replication is not induced) and they are automatically migrated to the new checkpoint format.

Thanks to Randall Leeds for the patch.

git-svn-id: c1f8a8ec0b3bb2e99ab3413722f81f687760e79c@965331 13f79535-47bb-0310-9956-ffa450edef68

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