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.
Adding ability to access local BitSet and to safely get a value at a given position
This commit makes three changes to the (PrimitiveKey)OpenHashMap

  1) _keySet  --renamed--> keySet
  2) keySet and _values are made externally accessible
  3) added an update function which merges duplicate values
This commit introduces the OpenHashSet and OpenHashMap as indexing primitives.

Large parts of the VertexSetRDD were restructured to take advantage of:

  1) the OpenHashSet as an index map
  2) view based lazy mapValues and mapValuesWithVertices
  3) the cogroup code is currently disabled (since it is not used in any of the tests)

The GraphImpl was updated to also use the OpenHashSet and PrimitiveOpenHashMap
wherever possible:

  1) the LocalVidMaps (used to track replicated vertices) are now implemented
     using the OpenHashSet
  2) an OpenHashMap is temporarily constructed to combine the local OpenHashSet
     with the local (replicated) vertex attribute arrays
  3) because the OpenHashSet constructor grabs a class manifest all operations
     that construct OpenHashSets have been moved to the GraphImpl Singleton to prevent
     implicit variable capture within closures.
Merge pull request #44 from jegonzal/rxinBitSet

Switching to VertexSetRDD to use @rxin BitSet and OpenHash
Merge branch 'master' of https://github.com/amplab/graphx into VertexSetWithHashSet
renamed update to setMerge
After some testing I realized that the IndexedSeq is still instantiating the array (not maintaining a view) so I have replaced all IndexedSeq[V] with (Int => V)