GIRAPH-775: Vertex value combiner (aching)
GIRAPH-775: Vertex value combiner (aching)

dcrankshaw/giraph,KidEinstein/giraph,apache/giraph,dukechain/giraph-1.2,korsvanloon/giraph,dukechain/giraph-1.2,dcrankshaw/giraph,KidEinstein/giraph,basio/graph,korsvanloon/giraph,KidEinstein/giraph,korsvanloon/giraph,apache/giraph,KidEinstein/giraph,apache/giraph,dukechain/giraph-1.2,dukechain/giraph-1.2,apache/giraph,dukechain/giraph-1.2,basio/graph,KidEinstein/giraph,apache/giraph,basio/graph,dcrankshaw/giraph,dukechain/giraph-1.2,dcrankshaw/giraph,korsvanloon/giraph,apache/giraph,KidEinstein/giraph,korsvanloon/giraph,korsvanloon/giraph,basio/graph