Matching PyMOAB compilers to those used to build the MOAB libraries.

This change is to support functions using/returning objects like std::string. Different compilers will generate different symbols depending on their version and the use of c++11. The ABI's of the compilers must match for the symbols to match in the MOAB and PyMOAB libraries.

These changes ensure that PyMOAB is built with the same compilers as the rest of the package.