coderplay/dragon — pull request #85 by coderplay (2012-07-25 06:04:19+00:00)
Title: Merge code from Min zhou, includes #73 #82  #80 #79

* Remove the package of dag
* #73 Add Mapper, Reducer and Partitioner
* Redesign EventProducer and EventEmitter
* Move the register method from AbstractWatchService to WatchService
* Remove the temporary Mapper and Reducer introduced by Jiannan
* WatchService should start watch quickly
* #82 Add child executor, which can execute map or reduce childs
* Let user can defined the mapper class and reducer class of a dragon job
* Delete SequenceFileEventProduer, because the inferfaces of EventProducer has changed