Implement get_fapl_mpio that returns the MPI communicator and info objects.

This implementation is based on the suggestion by Matthew Emmett
https://groups.google.com/d/topic/mpi4py/fxJFF7Hmx1Y/discussion

Follows gh-391
Change '*' import to specific names.
Implement custom path checker
Fix containership corner cases, improve tests
Make new containership test depend on HDF5 1.8.5+
Fix slash-handling glitch for containership tests
Merge pull request #394 from andrewcollette/issue_388

Implement custom containership test
Free MPI_Info and MPI_Comm Cython objects.
Merge pull request #395 from pdebuyl/get_fapl_mpio

implementation of get_fapl_mpio