Make initial_sync block for each replication
Make initial_sync block for each replication

It's low priority, and we don't want to overrun the server.  The
implementation is kinda hacky, it sticks the From into #job.pid while
the job is in the waiting queue.

fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb