Hostname match minion id.

Enforces hostname matching minion id. You should check your minion ids match your hostname before applying! Especially if you have [RabbitMQ](http://stackoverflow.com/questions/14659335/rabbitmq-server-fails-to-start-after-hostname-has-changed-for-first-time) installed.
The problem is that you have to restart the minion to update the grain.

Not sure what happens if you do that half way through a salt run.