Added the missing RowRowHad job test execution
Optimized the reduceRow/ColVectors function for the number of reducers
Merge pull request #561 from tomtau/develop

Added the missing RowRowHad job test execution
Merge pull request #564 from vitalyg/develop

Optimized the reduceRow/ColVectors function for the number of reducers
Merge pull request #562 from tomtau/feature/optimizedmatrix

Feature/optimizedmatrix - right row propagation + simple column sum optimization
Merge branch 'develop' of github.com:twitter/scalding into feature/optimizedmatrix
Changed SizeHint to use BigInt, added the J matrix test case