several larger changes came together, bit of cleaning too

- all code must be in functions (which must be in classes).
— changes a fair few tests
— also changes api, as method is not recursive, not passed around
- all state in instance vars in compiler (no accessors)
- class is another such variable, surely more coming
all green again

lib/parfait/list.rb

@@ -90,6 +90,7 @@ module Parfait
         return internal_object_get(index + 1)
       end
     end
+    alias :[] :get
 
     def empty?
       self.get_length == 0