* Implements a Peer RPC router that sends info to all Minio servers in the cluster.
* Bucket notifications are propagated to all nodes via this RPC router.
* Bucket listener configuration is persisted to separate object layer
file (`listener.json`) and peer RPCs are used to communicate changes
throughout the cluster.
* When events are generated, RPC calls to send them to other servers
where bucket listeners may be connected is implemented.
* Some bucket notification tests are now disabled as they cannot work in
the new design.
* Minor fix in `funcFromPC` to use `path.Join`
* Test code for controller-handler operations:
* Heal operations
* List operation
* Switch to "testing" lib, moving away from gocheck
* Minor refactors
* Remove extra call to initGracefulShutdown
* Remove dead code in mainControl:
Dead code found by the TestControlMain() test function that always
passes.
* Add tests for control-*-main.go
