GIRAPH-753: Efficient dense matrix aggregators (herald via apresta)
GIRAPH-756: Provide a way to halt running application (majakabiljo)
GIRAPH-771: Upgrade hive-io to 0.17 (majakabiljo)
GIRAPH-761: GiraphFileInputFormat ignores hidden file filter in
folders (Manuel Lagang via aching)
Refactored out SendCache to SendVertexIdDataCache and SendCache.
Everything compiles.
All tests should run.
Next step is to add a test for the vertex combiner.
Should have fixed.
Fixed one bug for byte array partition.
Fixed another bug for too small of a message buffer.
Rebased.
Rebased.
Passes tests.  Need to add two more tests.
1)  Test VertexInputFormat and edge input format.
Done
2) Add a test to check that the vertex value combiner works.
Done
3)  Run an experiment to see if it is faster with my changes.
Passed 'mvn clean verify'
4) Now the edges are added for combined vertices.
5) Clean up.
GIRAPH-775: Vertex value combiner (aching)
GIRAPH-776: Update Giraph to use HiveIO 0.18 (gmalewicz via majakabiljo)
GIRAPH-777: Fix bug from GIRAPH-775 (majakabiljo)
GIRAPH-778: Testing with TestGraph is broken (majakabiljo)
GIRAPH-779: Make it easier to reuse objects with hive-io input (majakabiljo)
GIRAPH-773
GIRAPH-786: XSparseVector create a lot of objects in add/write (ikabiljo via majakabiljo)
GIRAPH-787: Use HiveIO 1.9 (gmalewicz via aching)
GIRAPH-789: Upgrade hive-io to 0.20 - less metastore accesses (majakabiljo)
GIRAPH-790: Add a way to automatically retry a job (majakabiljo)
GIRAPH-791: HiveGiraphRunner picks -D options too late (majakabiljo)
GIRAPH-737: Giraph Application Master: Move to new and stable YARN API (mislam via ereisman)
GIRAPH-755: Make ZooKeeper port list available to input/output format (armax00 via claudio)
GIRAPH-738: Fix typos in quick start guide