start a new ruby layer to do the to_vool conversion

the "normalization" is getting more and more complicated and is not tested
And it seems i really don't like working with the untyped ast

lib/ruby/logical_statement.rb

@@ -0,0 +1,16 @@
+module Ruby
+  # Logical Statements are guaranteed to return boolean
+  # either :and or :or, which may be written as && and ||
+  class LogicalStatement < Statement
+    attr_reader :name , :left , :right
+
+    def initialize(name , left , right)
+      @name , @left , @right = name , left , right
+    end
+
+    def to_s(depth = 0)
+      at_depth(depth , "#{left} #{name} #{right}")
+    end
+
+  end
+end