AM: renames, default value for mask
AM: rename reduce_mass_matrix()
AM: wrap docstrings
AM: use print function in vib.py
AM: rename g_mat to g
AM: whitespace, docstring
AM: quick hack for mass weighted coordinate trafo
AM: .g() method should work for any shape
AM: harmonic analysis for PES Func with mass Metric
AM: comments and whitespace