Added first aggregation classes
Trying to get first aggregation running
Added emit to aggregation mapper
Added emit to aggregation mapper
Added most basic aggregations
Added count aggregation
Made generics on public interface easier for Java 6 / 7
Added way more aggregation tests
Added unittest for count aggregation, fixed this aggregation
Added distinct values aggregation
Made internal aggregation classes IdentifiedDataSerializable
Made KeyPredicateSupplier and PredicateSupplier IdentifiedDataSerializable
Changed internal mapreduce operations to cleaned API style
Added javadocs, fixed checkstyle and added unittests for client
Merge pull request #2598 from noctarius/mapreduce-aggregations

Mapreduce aggregations (Part 1)