Added --pjspi-clean-compile to setup script to have PJSIP compiled from scratch

darcs-hash:20090122142356-58103-8dd25790b34fe478642ce9c2771b2da0ec0cb8eb
Added instructions to compile from scratch to Updgrade.txt file after pulling i= line patch

darcs-hash:20090122142425-58103-24e031558922d8a1ea3697fc6f30bbc409ab64b8