# first option should specify the flash type.
# defaults to :error if not given
def flash_from_errors(object, *options)
  type = ([:notice, :error, :alert, :success, :news] & options)[0] || :error
  msg = object.errors.full_messages.join(", and ").downcase.capitalize
  options.include?(:now) ? flash.now[type] = msg : flash[type] = msg
end