send a 404 when downloading can't find artist or album. closes #70
send a 404 when downloading can't find artist or album. closes #70

neynah/groovebasin,sammcj/groovebasin,dwrensha/groovebasin,neynah/groovebasin,gorlug/groovebasin,gorlug/groovebasin,CalebMorris/groovebasin,Qbuer/groovebasin,emersion/groovebasin,neynah/groovebasin,dwrensha/groovebasin,melissanoelle/groovebasin,CalebMorris/groovebasin,dwrensha/groovebasin,andrewrk/groovebasin,Qbuer/groovebasin,melissanoelle/groovebasin,melissanoelle/groovebasin,gorlug/groovebasin,emersion/groovebasin,andrewrk/groovebasin,sammcj/groovebasin,andrewrk/groovebasin,CalebMorris/groovebasin,sammcj/groovebasin,dwrensha/groovebasin,emersion/groovebasin,Qbuer/groovebasin