RFE: deregister attributes

[Tom Goddard]

My mutation structure coloring code currently registers a Residue attribute called "mutation_score". Later the user may rename this. Then they may create a new attribute named "mutation_score". Only the attribute value type may be float the first time and int the second time. That gives an error. Is there a way when the user renames the attribute for me to deregister the attribute name? Or can I reregister changing float to int without an error? I did not see a way to do it.