Make clustering work

[ghost]

Fix for http://tickets.opscode.com/browse/COOK-2828

[michaelklishin]

@tchoi80 hardcoding node names in a cookbook is not a good idea. Neither is changing the default value
of node[:rabbitmq][:cluster].

Also note that running

rabbitmqctl stop_app && rabbitmqctl reset && rabbitmqctl start_app

is not equivalent to stopping the service. This will stop the app, reset the database (!!) and start it back. I don't think
resetting the database on every run is a very good idea either.

[ghost]

@michaelklishin,
OK. I reverted the attributes to their default values.

For the 'reset' command, it's not for stopping service, but for resetting the database as you said.
(Stopping service is done by 'execute' resource in the middle.)
And it isn't called on every run! Once the cookie is set, the block won't be called from next run!