add bindings for MAGMA-SPARSE libraries

[wingkitlee0]

I am thinking to extend the current magma.py to include magma-sparse routines. In particular, there are a few sparse linear solver that I want to use.

Any advice on how should I do that? I expect the new magma_sparse.py would have a lot of dependence on magma.py. On linux, libmagma_sparse.so depends on libmagma.so.

Also, one of the unmerged pull requests already have some of the wrapper written.