unrar:
 * workaround vfwprintf related "bus error" reported in [http://www.ip-phone-forum.de/showthread.php?t=262496 this thread]
 * the actual reason seems to be a bug in uClibc, it would be better to fix it instead
 * refs #1942


git-svn-id: file:///var/svn/freetz/trunk@11007 149334a1-2f27-0410-a3b9-fc62619ac1e6