add easyconfigs for Python 2.7.5 and zlib 1.2.8 dep
add easyconfigs for mpi4py on top of Python 2.7.3
change moduleclass to mpi for mpi4py
Merge pull request #276 from boegel/mpi4py_Python-2.7.5

add easyconfigs for Python 2.7.5 and mpi4py 1.3 for Python 2.7.3