Starting basic mpi setup.

Moved code over from my gist showing how to use cython to wrap mpi code.
Test problem in 2D using fftw-mpi.

Also added some basic instrumentation to fftwmpi files.
test.cpp will be removed once I have everything folded into python.
2D solver as a n object
Fixed minor error.

The inner loop was not checking i,j,k correctly.
Fixed incorect indexing in build 3D problem.

I was not handling the z offset.
3D test
Cleanup up plans in destructors.
Hold onto the test file for now.
Cython bindings for FFTWPoissonNDMPI objects.

Also added some write to file run from command line tests in testsolvers.