Implement Time.__copy__ and Time.__deepcopy__
Implement Time.__copy__ and Time.__deepcopy__

closes #891

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