Copy all environment variables when executing "./configure" and append our own CFLAGS to the ones already existing

darcs-hash:20090112112135-58103-c1a30560cfdd274311b252969982409d16a65c36
Added setup_pjsip.py to MANIFEST.in

darcs-hash:20090112114739-58103-8c32ebac97e809b36d00835f1c52a5fa37000631