make all instances attr read writers

unfortunately the writers have to have self.var =
otherwise it is just a local var
Also need to make the type explicit for all
Protocol included memory_length on the class for now

lib/parfait/data_object.rb

@@ -21,9 +21,7 @@
 # A marker class
 module Parfait
   class DataObject < Object
-    def initialize
-      super
-    end
+
     def self.integer_index
       type_length
     end