Fix wrong repldboff type which causes dropped replication in rare cases.
Return proper error on requests with an unbalanced number of quotes.
Replication: publish the slave_repl_offset when disconnected from master.

When a slave was disconnected from its master the replication offset was
reported as -1. Now it is reported as the replication offset of the
previous master, so that failover can be performed using this value in
order to try to select a slave with more processed data from a set of
slaves of the old master.
Redis 2.8.3.