Fixed HashMapExtractedFeatures bug, and created ArrayExtractedFeatures, which passes tests.
Removed the forced flush() on write for Kryo serialization of vectors and featuresets.
Setup the Kernel with a first try, LinearKernel to just translate features to vectors.
Started a PolynomialKernel implementation, to ease multi-feature combination engineering.
Landing, checkin
Added basic tree and bitshift implementation, started a test.
Added a silly baseline index, fixed up tests, and ran tests