add ability for fixed con_msg_manager to also be an endpoint_msg_manager

websocketpp/message_buffer/fixed.hpp

@@ -47,7 +47,7 @@ struct policy {
 
 /// A connection message manager that allocates a new message for each
 /// request.
-class con_msg_manager {
+class con_msg_manager : public lib::enable_shared_from_this<con_msg_manager> {
 public:
     typedef con_msg_manager type;
 
@@ -121,6 +121,14 @@ public:
             return false;
         }
     }
+
+    /// Get a pointer to a connection message manager
+    /**
+     * @return A pointer to the requested connection message manager.
+     */
+    ptr get_manager() {
+        return shared_from_this();
+    }
 private:
     message_ptr m_incoming_message;
     bool m_incoming_message_busy;