def glob_files(glob)
      absolute = 
      paths = if Pathname.new(glob).absolute?
        Dir[glob].sort
      else
        search_paths = (Jammit.asset_roots).map{ |path| File.join(path, glob) }
        Dir[*search_paths].sort
      end
      Jammit.warn("No assets match '#{glob}'") if paths.empty?
      paths
    end
def glob_files(glob)
      absolute = 
      paths = if Pathname.new(glob).absolute?
        Dir[glob].sort
      else
        search_paths = (Jammit.asset_roots).map{ |path| File.join(path, glob) }
        Dir[*search_paths].sort
      end
      Jammit.warn("No assets match '#{glob}'") if paths.empty?
      paths
    end
Absolute globs are absolute -- relative globs are relative to ASSET_ROOT.
 Print a warning if no files were found that match the glob.