update parfait message according to boot

most of the attributes are not used at compile time ,
so they did not get updated. But the compiler uses the attribute
names (which are correct as they are set in boot), so it’s nice
to actually see them in ruby too.

lib/parfait/message.rb

@@ -10,8 +10,14 @@
 module Parfait
   class Message < Object
 
-    attr_reader :locals , :receiver  , :return_value , :name
+    # :next_message => :Message, :receiver => :Object, :locals => :NamedList ,
+    # :return_address => :Integer, :return_value => :Integer,
+    # :caller => :Message , :name => :Word , :arguments => :NamedList
+
     attr_accessor :next_message
+    attr_reader   :receiver  , :locals
+    attr_reader   :return_address, :return_value
+    attr_reader   :caller , :name , :arguments
 
     def initialize next_m
       @next_message = next_m