Update mixin-column classes to have copy method that copies info
Update mixin-column classes to have copy method that copies info

larrybradley/astropy,mhvk/astropy,mhvk/astropy,tbabej/astropy,StuartLittlefair/astropy,lpsinger/astropy,DougBurke/astropy,StuartLittlefair/astropy,mhvk/astropy,stargaser/astropy,MSeifert04/astropy,larrybradley/astropy,saimn/astropy,MSeifert04/astropy,kelle/astropy,kelle/astropy,pllim/astropy,astropy/astropy,dhomeier/astropy,saimn/astropy,astropy/astropy,aleksandr-bakanov/astropy,tbabej/astropy,larrybradley/astropy,bsipocz/astropy,DougBurke/astropy,DougBurke/astropy,AustereCuriosity/astropy,joergdietrich/astropy,AustereCuriosity/astropy,joergdietrich/astropy,tbabej/astropy,AustereCuriosity/astropy,AustereCuriosity/astropy,stargaser/astropy,tbabej/astropy,dhomeier/astropy,astropy/astropy,kelle/astropy,StuartLittlefair/astropy,joergdietrich/astropy,pllim/astropy,larrybradley/astropy,DougBurke/astropy,funbaker/astropy,stargaser/astropy,aleksandr-bakanov/astropy,StuartLittlefair/astropy,mhvk/astropy,aleksandr-bakanov/astropy,bsipocz/astropy,kelle/astropy,AustereCuriosity/astropy,larrybradley/astropy,saimn/astropy,pllim/astropy,funbaker/astropy,kelle/astropy,pllim/astropy,saimn/astropy,funbaker/astropy,lpsinger/astropy,astropy/astropy,dhomeier/astropy,stargaser/astropy,lpsinger/astropy,lpsinger/astropy,joergdietrich/astropy,StuartLittlefair/astropy,lpsinger/astropy,dhomeier/astropy,mhvk/astropy,joergdietrich/astropy,dhomeier/astropy,aleksandr-bakanov/astropy,astropy/astropy,tbabej/astropy,saimn/astropy,pllim/astropy,MSeifert04/astropy,MSeifert04/astropy,funbaker/astropy,bsipocz/astropy,bsipocz/astropy