Progress toward mesh to mcnp geom.
Tweaks to material writting methods for MCNP and ALARA to return strings.
Fixed mcnp and alara Material methods naming.
Reimplimented write_mcnp and write_alara and corresponding tests.
Merge pull request #283 from elliottbiondo/mat_str

Material methods to return MCNP and ALARA strings.
I searched and replaced all molecular_weight and replaced them with molecular_mass
updating comments
updating comments and adding back liscense.txt
Merge branch 'staging' of https://github.com/pyne/pyne into mcnp_mesh
Working version of mesh_to_geom.
mesh_to_geom tests written and passing.
Added example of pyne.ace usage in an ipython notebook.
Fixed doc string, eliminated superfluous len() calls.
Removed accidently committed change.
Merge branch 'mcnp_mesh' of https://github.com/elliottbiondo/pyne into elliottbiondo-mcnp_mesh
fixed parameters typo
init'd cli sub-package
sleepy
created origen nuclide data sets.
tape9 cli runs!