Linear Algebra routines as generalized ufuncs

This pull request contains a module with some lineal algebra functions implemented as generalized ufuncs. It is implemented using LAPACK/BLAS, and it is configured to compile using the same LAPACK/BLAS configuration as numpy.linalg. It also includes some extras, like some fused arithmetic ufuncs (multiply_add and similar ones).

More information can be found in gufuncs_linalg_contents.rst