SERVER-14419 Correctly parse the "masterHost" argument to Cloner::go into a ConnectionString, not a HostAndPort.

The argument represents a ConnectionString, but we parse it into a HostAndPort
when doing isSelf checks.  This was an error before that led checks to succeed
incorrectly, but fails with the new HostAndPort parsing code from SERVER-14419.
SERVER-14419 Introduce unittest of HostAndPort; make ":123" unparseable due to lack of host component.
SERVER-14419 Implement HostAndPort::parse.
SERVER-14426 Add a StringData method to BSONElement
SERVER-14318 Use structs for replication command arguments
SERVER-14254 convert _v8_function from function pointer to boolean
SERVER-14254 (v8-3.25) convert _v8_function from function pointer to boolean
SERVER-14254 added jstest for _v8_function.toString()
BUMP 2.7.3
post 2.7.3
SERVER-14135 implement processHandshake() in LegacyReplicationCoordinator
SERVER-14135 implement getElectionId() in LegacyReplicationCoordinator
SERVER-14135 implement waitUpToOneSecondForOptimeChange() in LegacyReplicationCoordinator
SERVER-14135 implement shutdown() in LegacyReplicationCoordinator
SERVER-14135 implement buildsIndexes() in LegacyReplicationCoordinator
SERVER-14135 implement getHostsWrittenTo() in LegacyReplicationCoordinator
 SERVER-14135 remove some usage of godMode and replSet bool from LegacyReplicationCoordinator