fixed problem with opening client and server. in some cases it

would fail to open in such a way that it could never succeed
but it'd never stop retrying.  now terminating when open fails
such that it'll never succeed.

lib/platform/CXWindowsScreen.cpp

@@ -197,7 +197,7 @@ CXWindowsScreen::open()
 	log((CLOG_DEBUG "XOpenDisplay(\"%s\")", display));
 	m_display = XOpenDisplay(display);
 	if (m_display == NULL) {
-		throw XScreenOpenFailure();
+		throw XScreenUnavailable(60.0);
 	}
 
 	// get root window