message: ocaml.Dependencies: Pretty print.
diff: @@ -178,6 +178,9 @@ class Ocamldep(drake.Builder):
  self.__toolkit = toolkit
  super().__init__([source], [target])
  + def __str__(self):
  + return 'dependencies of {}'.format(self.__source)
  +
  def execute(self):
  return self.cmd('Dependencies {}'.format(self.__target),
  self.__toolkit._dependencies_command(self.__source, self.__config),
  