Fix GroupedTable __getitem__ to select columns or slice
Fix GroupedTable __getitem__ to select columns or slice

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