Removed unused 'failover_node' and 'respawn_node' functions

Change-Id: I568b44b11fd755bd3d6db1ce671accc747f134b1
Reviewed-on: http://review.couchbase.org/28044
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>