A fully templated, header-only version of RedSVD.
This is a refactoring of RedSVD that removes dependency on scalars of type float by explicitly templating all types in the same way the Eigen library does.
This makes it possible to use RedSVD for matrix types other than MatrixXf.
All three classes RedSVD, RedSymEigen and RedPCA can be found in the include/RedSVD/RedSVD-h header file.