Pythonsht

Created by: pchanial

With these commits, I could build and test the python extension using:

autoconf
CC=mpicc ./configure --enable-mpi --enable-pic
make python/libsharp/libsharp.so

Compatibility with mpi4py 1.3.1 is good to have since:

• it's the latest stable version (and the one available at pypi)
• on supercomputers such as Curie or Edison, it's usually a pain in the neck not to use the provided mpi4py (which is not the dev version)