Added a number of very fast, memory-efficient data structures: BitSet, OpenHashSet, OpenHashMap, PrimitiveKeyOpenHashMap.
removing unused commented code
added lineage tracking code
Removing potential additional shuffle dependency where an already partitioned RDD[(Vid, VD)] is repartitioned.
removing completely unnecessary map operation.
Adding additional type constraints to VertexSetRDD to help diagnose issues with recent benchmarks.
Merge branch 'hash1' of https://github.com/rxin/incubator-spark into rxinBitSet
Added bitset to kryo register
Adding logical AND/OR, setUntil, and iterators to the BitSet.
Switching to the @rxin BitSet implementation for VertexSet Value tables.
Merge pull request #43 from amplab/FixBitSetCastException

Fix BitSet cast exception
Merge pull request #41 from jegonzal/LineageTracking

Optimizing Graph Lineage
Merging with upstream master.
Merge branch 'master' of github.com:amplab/graphx
Merge pull request #44 from jegonzal/rxinBitSet

Switching to VertexSetRDD to use @rxin BitSet and OpenHash
Added logging to Graph, GraphLab, and Pregel.
Merge branch 'master' of github.com:amplab/graphx