Added text about preloading and stack use to su/su_alloc.c.
Added text about preloading and stack use to su/su_alloc.c.

darcs-hash:20060428100538-65a35-cf7305e99b67329987fd601eaf567232eca01b4c.gz

unispeech/sofia-sip,jart/sofia-sip,xhook/sofia-sip,xhook/sofia-sip,unispeech/sofia-sip,xhook/sofia-sip,unispeech/sofia-sip,xhook/sofia-sip,BelledonneCommunications/sofia-sip,erdincay/sofia-sip,erdincay/sofia-sip,xhook/sofia-sip,BelledonneCommunications/sofia-sip,BelledonneCommunications/sofia-sip,BelledonneCommunications/sofia-sip,erdincay/sofia-sip,erdincay/sofia-sip,unispeech/sofia-sip,jart/sofia-sip,jart/sofia-sip