Define _GNU_SOURCE in the CFLAGS.
Update the README.
Remove the duplicate Gentoo init script ndhc.sh that is in the root.
Remove DESIGN -- it's outdated.
ifchd if it is necessary to do so, just as is the case for other keywords.
Make data sending in ifchange_*() collect all keywords into a buffer that
is sent in a single sockwrite() rather than performing a sockwrite() for
every keyword.
Minor documentation updates.
jail and change configuration instructions as well.
Change default configuration instructions to specify setting root
of the chroot jail as owned by root.root.
