class Ronn::Template

def style_files

the stylesheets array.
resulting array will include nil elements in positions corresponding to
Array of expanded stylesheet file names. If a file cannot be found, the 
def style_files
  styles.map do |name|
    next name if name.include?('/')
    style_path.
      reject  { |p| p.strip.empty? }.
      map     { |p| File.join(p, "#{name}.css") }.
      detect  { |file| File.exist?(file) }
  end
end