minor cleanup

include/libtorrent/alert_manager.hpp

@@ -183,7 +183,8 @@ namespace libtorrent {
 
 		// this is either 0 or 1, it indicates which m_alerts and m_allocations
 		// the alert_manager is allowed to use right now. This is swapped when
-		// the client calls get_all(), at which point 
+		// the client calls get_all(), at which point all of the alert objects
+		// passed to the client will be owned by libtorrent again, and reset.
 		int m_generation;
 
 		// this is where all alerts are queued up. There are two heterogenous

include/libtorrent/aux_/session_impl.hpp

@@ -778,8 +778,6 @@ namespace libtorrent
 			// to clear the undead peers
 			boost::optional<io_service::work> m_work;
 
-			typedef std::list<boost::shared_ptr<torrent> > check_queue_t;
-
 			// this maps sockets to their peer_connection
 			// object. It is the complete list of all connected
 			// peers.
@@ -1140,6 +1138,7 @@ namespace libtorrent
 			external_ip m_external_ip;
 
 #ifndef TORRENT_DISABLE_EXTENSIONS
+			// this is a list to allow extensions to potentially remove themselves.
 			typedef std::list<boost::shared_ptr<plugin> > ses_extension_list_t;
 			ses_extension_list_t m_ses_extensions;
 #endif

src/session_impl.cpp

@@ -886,7 +886,7 @@ namespace aux {
 		m_alerts.add_extension(ext);
 		ext->added(this);
 	}
-#endif
+#endif // TORRENT_DISABLE_EXTENSIONS
 
 #ifndef TORRENT_NO_DEPRECATE
 	feed_handle session_impl::add_feed(feed_settings const& sett)