Improve error throwing in RollupEventSerializer
Change the expected error
Change the comment RTE->IOError
Merge pull request #244 from chinmay-gupte/refactor_serializer_a_bit

Refactor error handling in RollupEventSerializer
Merge remote-tracking branch 'racker/master' into bf_cloudfiles

Conflicts:
	blueflood-core/src/main/java/com/rackspacecloud/blueflood/outputs/serializers/RollupEventSerializer.java