Samza: allow EPI with no output stream, remove a redundant property
configurable hdfs dir for SAMOA
Fix bug with empty serialized map (of PIs)
Source delay: delay between batches of instances
Add kryo registration for Perceptron and TargetMean in AMRules
Merge pull request #93 from caseyvu/samza

Improvements for Samza engine
Merge pull request #1 from yahoo/master

sync