def alias(name, &block)
      al = Alias.new(self, name, :logger => logger)
      block ? block.call(al) : al
    end
def alias(name, &block)
      al = Alias.new(self, name, :logger => logger)
      block ? block.call(al) : al
    end
Returns a Stretcher::Alias object for the alias +name+.
 Optionally takes a block, which will be passed a single arg with the Alias obj
 The block syntax returns the evaluated value of the block

   my_server.alias('user_1') # Stretcher::Alias
   my_server.alias { |alias| 1 } # 1