implemented __getitem__ and __len__ in quantity
implemented __getitem__ and __len__ in quantity

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