Cofactors and adjugates of matrices

[Spidy104]

Add feature to find the determinants, cofactors, and adjugates of matrices.

[celonymire]

Note that determinant is already implemented as an algorithm in <mpp/algo/det.hpp> (mpp::det CPO). The other two should be easy enough to add soon.

[Spidy104]

Ohh, yes, I forgot, I am happy to contribute, am I allowed!

[celonymire]

Ohh, yes, I forgot, I am happy to contribute, am I allowed!

Ah yes, you can contribute! This is a public project after all :D

If you have any questions, feel free to discuss them here.