implement Path::join()

src/lib/src/Path.cc

@@ -22,8 +22,10 @@ namespace jes
 
     Path Path::join(const Path & other)
     {
-        // TODO
-        return "";
+        if (m_path.size() > 0 && *m_path.rbegin() == '/')
+            return Path(m_path + other.m_path);
+        else
+            return Path(m_path + '/' + other.m_path);
     }
 
     void Path::clean()