def absolute_path(asset_pathname, css_pathname)
      (asset_pathname.absolute? ?
        Pathname.new(File.join(Jammit.public_root, asset_pathname)) :
        css_pathname.dirname + asset_pathname).cleanpath
    end
def absolute_path(asset_pathname, css_pathname)
      (asset_pathname.absolute? ?
        Pathname.new(File.join(Jammit.public_root, asset_pathname)) :
        css_pathname.dirname + asset_pathname).cleanpath
    end
Get the site-absolute public path for an asset file path that may or may
 not be relative, given the path of the stylesheet that contains it.