Show <activity:subject> in Atom group notice feed
Show <activity:subject> in Atom group notice feed

Version 0.9.6 and below of StatusNet assume anything in <author> is a
Person. So, we include an <activity:subject> element, which will be
checked first by those versions of the code, only for group feeds.

At some point we'll take this out, but it's useful for now.

d3vgru/StatusNet,charlycoste/StatusNet,charnimda/lgbtpzn-social,foocorp/gnu-social,eXcomm/gnu-social,eXcomm/gnu-social,minmb/statusnet,csarven/statusnet,UngPirat/freesocial,minmb/statusnet,sikevux/bsk-social,faulteh/gnu-social,zh/statusnet,faulteh/gnu-social,zcopley/zcopleys-statusnet-clone,bankonme/gnu-social,sikevux/bsk-social,zcopley/StatusNet,csarven/statusnet,Piratas/tortuga,gnusocial/mainline,gnusocial/mainline,eXcomm/gnu-social,furtherfield/gnu-social,Piratas/tortuga,UngPirat/freesocial,charlycoste/StatusNet,furtherfield/gnu-social,zh/statusnet,foocorp/gnu-social,foocorp/gnu-social,zcopley/StatusNet,bankonme/gnu-social,zcopley/zcopleys-statusnet-clone,studio666/gnu-social,bankonme/gnu-social,bankonme/gnu-social,UngPirat/freesocial,charnimda/lgbtpzn-social,studio666/gnu-social,sikevux/bsk-social,studio666/gnu-social,zh/statusnet,xebia/statusnet-oauth2,xebia/statusnet-oauth2,furtherfield/gnu-social,charlycoste/StatusNet,minmb/statusnet,chimo/social,gnusocial/mainline,Piratas/tortuga,gnusocial/mainline,zcopley/StatusNet,faulteh/gnu-social,xebia/statusnet-oauth2,chimo/social,d3vgru/StatusNet,faulteh/gnu-social,csarven/statusnet,furtherfield/gnu-social,d3vgru/StatusNet,zcopley/zcopleys-statusnet-clone,chimo/social,csarven/statusnet,Piratas/tortuga,studio666/gnu-social,charnimda/lgbtpzn-social,sikevux/bsk-social,eXcomm/gnu-social