Add plural support for minutes/hours/days/months ago.
Add plural support for minutes/hours/days/months ago.

Reapply of revised b27882c9166191de4aaea298ba1b1a524cfe9ac7 that was reverted by Brion Vibber in 2d4c0f9a47f6534c578a37abe79670cec699caae.

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