#466 - Make behaviour of appliesTo and matchStage same.

Based on conversation [here](https://github.com/gocd/gocd/pull/466#issuecomment-54858718) and [here](https://github.com/gocd/gocd/pull/466#issuecomment-54869963), making stageMatches and appliesTo almost the same, except that stageMatches checks the event type as well.