Fix ruby normalising to_vool

So that vool layer never has complex conditions or returns
Start with while, next if, return and assign

lib/ruby/variables.rb

@@ -23,8 +23,8 @@ module Ruby
     def add_ivar( array )
       array << @name
     end
-    def to_s
-      "@#{name}"
+    def to_s(depth = 0)
+      at_depth(depth , "@#{name}" )
     end
   end