Break out json into json_lines so that users streaming json can use the line delimited codec and users using message based transports i.e. redis can still use a codec without requiring the message end in '\n'
Add more descriptive docs for json/json_lines codecs
Merge pull request #731 from logstash/json-streaming

Break out json/json_lines codec.
Merge git://github.com/logstash/logstash