SERVER-9253 added pid_file argument to mongo_killproc. New usage: mongo_killproc pid_file procname
SERVER-14446 Add ability to save config to ReplCoordinatorExternalState.
SERVER-14446 Use _setCurrentRSConfig to update TopologyCoordinator's config.

It is now only legal to call from within the ReplCoordinator's
ReplicationExecutor context, but this change ensures that the replication
coordinator and topology coordinator keep their view of the replica set
configuration in sync.
Merge remote-tracking branch 'upstream/master'