Refactored common Postgresql code into postgresqlutils and improved documentation for where postgresqlconf lives.
postgresql.replication.upstream.lag.time - Milliseconds since pg_last_xact_replay_timestamp
postgresql.replication.upstream.lag.bytes - The difference, in bytes, between pg_last_xlog_receive_location and pg_last_xlog_receive_location
postgresql.replication.downstream.count - The number of walreceivers connected to the DB
postgresql.replication.downstream.lag.bytes - The difference, in bytes, between the sent location and the replayed location for each walreceiver
postgresql.replication.recovering - The value of pg_is_in_recovery
postgresql.replication.walreceiver.running - One if a walreceiver process is running on the machine, otherwise zero.

…ecovery.

…-replication