Prevent operator chaining directly after iteration nodes.
Fix NepheleJobGraphGenerator bug with iterations

When traversing it is not checked whether iterations where already
visited, this led to a bug when you used the output of an iteration
twice.
Use JAVA_RUN in all start scripts
[ci skip]
Added test case to check compiler with plans branching directly after a loop.
Implemented ordering within groups in optimizer.
Added tests.
Cleaned up property matching/reasoning for dual input operators.
Remove IPv4 Stack Hint
[ci skip]
Maven requirements [ci skip]
Cleaned up wordcount examples.
Re added accidentally lost WordCountArrayTuples example.
Improved handling of probelm causes and better error messages when connecting to HDFS for hdfs resident files.

Added HDFS as dependency to pact-client, to allow local-executor to access hdfs files.
Fix1: Combiner gets same DOP and SubtasksPerInstance as its input to be chainable
Fix2: Local strategy of stand-alone (non-chained) combine driver
      Adapted CombineTask tests to new local strategy
Fixed instantiation of utility combine node to use the correct properties.
Fix for Issue #93: slaves file requires blank line at end (otherwise last slave won't be started)
change deploy tool to detect current stratosphere version and dynamically generate the yarn build
Fixed typo in method name
Removed unnecessary import from RequestedLocalProperties.
Small fix in PactRecordComparator
Reenabled range partitioning with manually specified data distributions.
- Added Generics to DataDistribution
- Added range partitioning to output emitter
- Adapted output emitter tests
- Added PactRecordDataDistribution and corresponding test
- Reactivated pact tests with range distribution.
- Reincluded TeraSort Pact Java example into example jobs.
Merge pull request #223 from rmetzger/fix_deploy_tool

change deploy tool to detect current stratosphere version
Hotfixing version detection
Add renaming utility to master branch