LA: rename Matrix.FoldRows to FoldByRow; FoldColumns to FoldByColumn
LA: Split Matrix.Map into Map and MapConvert to allow optimizing common inplace case
LA: Matrix.FoldByRow/Column operates on arrays to allow arbitrary types (not just those supported by vectors)
LA: Matrix Column/Row sums and absolute-sums
LA: matrix row/column vector fold and reduce routines
LA: F# modules add DiagonalMatrix module to create diagonal matrices
LA: F# modules matrix sumRows, sumAbsRows, normRows and same for columns
Release: v3.0.0-beta04