Added wrapper for Wccl::Expression

swig/libcclexpression.i

@@ -14,6 +14,7 @@ namespace Wccl {
   class Expression : boost::noncopyable {
   public:
     virtual std::string to_string(const Corpus2::Tagset& tagset) const = 0;
+    std::string to_raw_string() const;
   };
 }