answer some commented questions

src/arch/InputHandler/InputHandler_X11.cpp

@@ -201,7 +201,7 @@ void InputHandler_X11::Update()
 			lastEvent.type = 0;
 		}
 
-		// Why only the zero index?
+		// Get the first defined keysym for this event's key
 		lastDB = XSymToDeviceButton( XLookupKeysym(&event.xkey, 0) );
 
 		if( lastDB == DeviceButton_Invalid )

src/arch/LowLevelWindow/LowLevelWindow_X11.cpp

@@ -161,7 +161,8 @@ RString LowLevelWindow_X11::TryVideoMode( const VideoModeParams &p, bool &bNewDe
 		XSelectInput( Dpy, Win, winAttrib.your_event_mask | StructureNotifyMask );
 		XMapWindow( Dpy, Win );
 
-		// XXX: Why do we need to wait for the MapNotify event?
+		// Wait until we actually have a mapped window before trying to
+		// use it!
 		while( true )
 		{
 			XEvent event;