Changed magnet metadata handling and added 'magnet.path.set'.

src/core/manager.cc

@@ -132,6 +132,16 @@ Manager::retrieve_throttle_value(const torrent::Object::string_type& name, bool
   }
 }
 
+void
+Manager::set_magnet_path(const std::string& path) {
+  if (path.empty())
+    m_magnet_path.clear();
+  else if (path.back() == '/')
+    m_magnet_path = path;
+  else
+    m_magnet_path = path + '/';
+}
+
 void
 Manager::cleanup() {
   // Need to disconnect log signals? Not really since we won't receive