Termination Criterion and PageRank for the new Java API
Optimization of SimplePagerank, setting of a correct serializer for the termination criterion, empty implementation of combiners for cogroup
Add utility result verification method for K/V pairs with double value and delta threshold.
Allow bulk iteration termination criterion with different data type than partial solution
Cleaned up page rank example and adjusted tests
getAggregators() for SpargleIteration
Tests for aggregate operator
Cache: exists() called / rel. path support
Fix aggregation tests
Fix error message for unsupported averaging data type
Generalised the name of the expected InputSplit class in HadoopDataSource.
Add avro to stratosphere-dist, thus adding it to the lib/ folder
Better estimations for filter operator
Corrected minor errors in the optimizer filter operator.
Add getSolutionSet() and .getWorkset() for delta iterations

Before, the result of dataset.iterateDelta() would be the workset and
the solution set could be obtained via iteration.getSolutionSet().

This is confusing since you are not told what the result of
.iterateDelta() is supposed to be. Now, when using the result an
exception is thrown during pre-flight that advises the user to use
the two methods to get the correct dataset (work, solution).
Rename DeltaIterativeDataSet -> DeltaIteration, is no DataSet anymore

Now a user cannot mistakenly use it as a data set but is forced to use
the .getSolutionSet() and .getWorkset() methods.
added ExEnv.registerCachedFile()
StringComparators uses static StringValue.readString()
Fix generic compiler problem with Java 6
Test case for showing the still existing BulkIteration bug.
Added comments to iterative data set.
Cleaned up and  adjusted BulkIterationWithAllReducerITCase