type now means class name

update reader (with new type definition)
remove type class (now symbol)
update all types to class name symbols

lib/parfait/variable.rb

@@ -2,7 +2,7 @@ module Parfait
   class Variable < Object
 
     def initialize type , name , value = nil
-      raise "not type #{type}" unless type == :ref or type == :int
+      raise "not type #{type}" unless Virtual.machine.space.get_class_by_name(type)
       self.type , self.name , self.value = type , name , value
       self.value = 0 if self.type == :int and value == nil
       raise "must give name for variable" unless name