hadoopcompatibility: Implementations of basic programming interfaces and...

... a basic driver.

* wrappers for Mapper, Reducer and Combiner (as a local Reducer) on the new Java API
* wrapper for OutputCollector
* wrappers for Partitioner, values comparator.
* a driver making it posible to run unmonitored (so far)  Hadoop jobs on Flink.
* tests and variations of the WordCount driver exclusively in Hadoop.

You can find more about the Google Summer of Code project here:  https://issues.apache.org/jira/browse/FLINK-838?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14031511
My intuition is that it would be good to have as many slots as requested tasks if a job is locally run from an IDE. If you run a program with DOP > 1 from an IDE, you want to test if it is working correctly when run in parallel or debug it. So in this case the slot mechanism should be somehow deactivated (or as many slots created as the max DOP of the job to run).
I'm not so familiar with the scheduling code. @StephanEwen can this be done somehow?