STORM-586: TridentKafkaEmitter should catch updateOffsetException.

I think UpdateOffsetException shouldn't extend FailedFetchException . They meant to be different exceptions . The problem here is if a method throws UpdateOffsetException and there is a catch for FailedFetchException its get caught in that catch but we want to have different behavior for FailedFetchException and UpdateOffsetException. Also UpdateOffsetException can be named differently, may be TopicOffsetOutOfRangeException and for any other errors use FailedFetchException.