Support \n as new line delimiter for EventSource

EventSource spec allows to use \n only as end of line delimiter (http://www.w3.org/TR/eventsource/#parsing-an-event-stream). The current tests force \r\n.

I cached this working on an implementation of SockJS for the Play Framework, which natively supports EventSource, but uses \n as the delimiter. I believe is a valid case for the tests to support either, as browsers should.