Simple protein analysis.

Example::

X = ProteinAnalysis("MAEGEITTFTALTEKFNLPPGNYKKPKLLYCSNGGHFLRILPDGTVDGTRDRSDQHIQLQLSAESVGEVYIKSTETGQYLAMDTSGLLYGSQTPSEECLFLERLEENHYNTYTSKKHAEKNWFVGLKKNGSCKRGPRTHYGQKAILFLPLPV")
print(X.count_amino_acids())
print(X.get_amino_acids_percent())
print(X.molecular_weight())
print(X.aromaticity())
print(X.instability_index())
print(X.flexibility())
print(X.isoelectric_point())
print(X.secondary_structure_fraction())
print(X.protein_scale(ProtParamData.kd, 9, 0.4))
print(X.molar_extinction_coefficient())