Make hashing functions more concise and move hashes to c++

As was discussed the hashing functions have been made more concise and
combined into a single file. The stored hashes have been moved to
data.cpp and are accessible through pyne.data. Docstrings were also
added.
PEP8 style changes to nuc_data_make

remove lots of trailing spaces at the end of lines and adding spaces
after commas and between +’s.