Add end-of-game dumplogs

This is based on the "new" dumplog patch for 3.6.0, by Maxime Bacoux.

Define DUMPLOG to enable. By default only enabled for the TTY linux.

src/sys.c

@@ -31,6 +31,9 @@ sys_early_init()
     sysopt.debugfiles = (char *) 0;
 #else
     sysopt.debugfiles = dupstr(DEBUGFILES);
+#endif
+#ifdef DUMPLOG
+    sysopt.dumplogfile = (char *) 0;
 #endif
     sysopt.env_dbgfl = 0; /* haven't checked getenv("DEBUGFILES") yet */
     sysopt.shellers = (char *) 0;
@@ -95,6 +98,10 @@ sysopt_release()
     if (sysopt.debugfiles)
         free((genericptr_t) sysopt.debugfiles),
         sysopt.debugfiles = (char *) 0;
+#ifdef DUMPLOG
+    if (sysopt.dumplogfile)
+        free((genericptr_t)sysopt.dumplogfile), sysopt.dumplogfile=(char *)0;
+#endif
     if (sysopt.genericusers)
         free((genericptr_t) sysopt.genericusers),
         sysopt.genericusers = (char *) 0;