Cython api for lapack and blas

- [x] Add interface for lapack and blas routines.
- [x] Add working example in tests
- [ ] Review signatures for correctness
- [x] Add function to get directory of `scipy.linalg` (similar to `numpy.get_include`)
- [x] Finish wrappers for 'gees' and 'gges' functions.
- [x] Add interfaces to the functions added in https://github.com/scipy/scipy/pull/3984
- [x] Add this api to the documentation
un -> or, as above