Added better error checking to nua_creq_msg().
Added better error checking to nua_creq_msg().

Fixed Service-Route header processing, too.

darcs-hash:20060425154524-65a35-7bfd40c96a82906f31cf51363ab649951138125e.gz

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