Lift const from Sentence::id_ and add id setter + swig wrapper for it.

CMakeLists.txt

 PROJECT(Corpus2Library)
 
 set(corpus2_ver_major "1")
-set(corpus2_ver_minor "3")
-set(corpus2_ver_patch "4")
+set(corpus2_ver_minor "4")
+set(corpus2_ver_patch "0")
 
 cmake_minimum_required(VERSION 2.8.0)
 

libcorpus2/sentence.h

@@ -118,12 +118,17 @@ public:
 		return id_;
 	}
 
+	/// Identifier setter
+	void set_id(const std::string &id) {
+		id_ = id;
+	}
+
 protected:
 	/// The tokens this sentence contains and owns
 	std::vector<Token*> tokens_;
 
 	/// The sentence identifer - default is empty
-	const std::string id_;
+	std::string id_;
 };
 
 } /* end ns Corpus2 */

swig/sentence.i

@@ -48,6 +48,8 @@ namespace Corpus2 {
 
     const std::string id() const;
 
+    void set_id(const std::string &id);
+
     %extend {
       static boost::shared_ptr<Corpus2::Sentence> create_sent(const std::string &id) {
         return boost::shared_ptr<Corpus2::Sentence>(new Corpus2::Sentence(id));