GIRAPH-673: Input superstep should support aggregators like any
other superstep (Bingjing via aching)
GIRAPH-683: Jython for Computation (nitay)
GIRAPH-694 Setting configuration in GiraphConfiguration causes
non thread safe copies (aching)
GIRAPH-623: Website Documentation: table of parameters
GIRAPH-695: Add getCombiner and getComputation methods for
MasterCompute (aching)
GIRAPH-696: Should be able to spill giraph metrics to a specified directory on HDFS
GIRAPH-697: Clean up message stores (majakabiljo)
GIRAPH-693: Giraph-Hive check user code as soon as possible (nitay)