Converted for loops to while loops in EdgePartition.
Merge pull request #54 from amplab/rxin

Converted for loops to while loops in EdgePartition.
Changing Pregel API to operate directly on edge triplets in SendMessage rather than (Vid, EdgeTriplet) pairs.
Merge pull request #56 from jegonzal/PregelAPIChanges

Changing Pregel API to use mapReduceTriplets instead of aggregateNeighbors
Optimize mrTriplets for source-attr-only mapF using bytecode inspection