gnome-bluetooth and various fixes

Did a good bugfixes day yesterday :
-crasher in gnome-bluetooth was quite tricky to find, so let's share it with all GNOME hackers who are using gob. Be extra careful with destroywith, because it requires as parameter a function with void (*func) (void*) signature (ie like g_object_unref). If you were using it with gdk_pixbuf_unref or gnome_vfs_file_info_unref, with older gcc, it was ok. But with gcc 3.4, you'll get a warning (easy to miss when not compiling with -Werror) stating program will abort if this code is reaching (I wonder why it is only a warning), and guess what : your program will segfault as stated.. So, get prepared, use g_object_unref when possible or handle finalisation yourself with destroy command.
-fix a crazy bug in latest magicdev : cooker users where complaining k3b was starting without them doing anything when they login. Magicdev was supposed to only mount CDs at login, not also run cd burner or player :)
-found a missing i18n init by chance in nautilus-cd-burner nautilus extension. I'm quite afraid to discover nobody ever found it, probably guessing translation for this module wasn't complete in their language. So, if you find part of a module which is not translated, when this module is run inside another one (nautilus extension is a good example), check po file for your language and if it is translated, bugzilla !!
-with our XFree86 security update, our support guy discovered strange behaviour with fonts disappearing in fontconfig. It seems we are are to fool fontconfig dirty cache detection. Will fix today.