Highlights:
-------------- 
- Experiment module yarn. Run gearpump over yarn
- Experiment module storm connector. We now can run storm-benchmark with this.
- Add several timechats widgets in UI,

Change List:
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 - #654, Use yarn to distribute whole gearpump package instead of jars
 - #631, remove unnecessary storm dependencies
 - #652, log conflict between slf4j and log4j
 - #652, log is muted when running on yarn
 - #650, remove logback classic slf4j binding from classpath
 - #648, yarn unable to start worker
 - #27, Integrate YARN into scheduler
 - #643: metrics tables are now sortable
 - #639, fix parallelism is 0 on GlobalGrouping
 - #636, fix FieldsGroupingPartitioner
 - #629 - query backend for actual websocket address 
 - #634: create websocket can be failed when url is undefined
 - #415, support storm connector
 - #613, Show metrics charts in application's detail page
 - #546 add a rest api to query WebSocket url
 - #624, add description field to TaskDescription
 - #434 add api/v1.0 prefix for all rest services
 - #618 fix no data returned when call Metrics rest
 - #607, bump up kafka version to 0.8.2.1
 - #615, Incorrect Dag edge width
 - #608 increase the maximum frame size of Akka
 - #611: dag looks more elegant