- Added PHP_PROG_SED which checks whether the sed in system works with

- Added PHP_PROG_SED which checks whether the sed in system works with
  very long strings.

#
# Sascha, is this okay? I added this here since any libtool/autoconf
# release out there doesn't have this yet..we can remove this when
# we can really start requiring such versions which have it?
#
# This sets $SED to the correct binary, so that should be used in
# places were the lines might be very long.
#