Ugly brute-force method for avoiding a double-free segfault on exit.
Better patch welcome.

--- a/spacerider.cpp.orig	2015-03-31 23:24:17.770966147 -0400
+++ b/spacerider.cpp	2015-03-31 23:24:41.592174463 -0400
@@ -306,8 +306,6 @@
 		/* free screen */
 		SDL_FreeSurface(screen);
 	}
-	/* call the TTF-Library cleanup function */
-	TTF_Quit();
 
 	/* call the NET-Library cleanup function */
 	SDLNet_Quit();