Separated the special case in Product
Added the row propagation
Added a simple, but hopefully correct (when multiplied by a zero matrix) Hadamard product
private vals for special case in Product
Collect addends returning TypedPipes, not wrapping in matrices
getCol/getRow using Ordering.equiv
Hadamard product without a join
Merge pull request #562 from tomtau/feature/optimizedmatrix

Feature/optimizedmatrix - right row propagation + simple column sum optimization