Authors:
Pedro Delicado [aut] (Original C++ author)
,
Mario Huerta [aut] (Original C++ author)
,
Kevin Michael Frick [trl, aut, cre] (Modern C++ fixes and Rcpp port
,
with permission from the original authors)
,
Stephen L. Moshier [cph] (Author of eigens() for symmetric matrix
eigendecomposition)