MEM: Allow loading modern maps.

Stop gap fix for QW-Group#665. Could include some detection of memory to avoid
allocating 256MB if system is puny. Ideal solution would be dynamic
allocation.

sys_posix.c

@@ -335,7 +335,7 @@ int main(int argc, char **argv)
 	if (COM_CheckParm(cmdline_param_client_nostdoutput))
 		sys_nostdout.value = 1;
 
-	Host_Init (argc, argv, 128 * 1024 * 1024);
+	Host_Init (argc, argv, 256 * 1024 * 1024);
 
 	oldtime = Sys_DoubleTime ();
 	while (1) {