* Exclude some files from the stage3 tarball to be installed in the chroot.
This reduces the number of etc-updates that need to be process.
* Manually eselect profile. This is needed now because /etc/portage/make.profile
is excluded above.
* Use m4 and a template (in file) to create /etc/fstab instead of using sed.
* Add a "software" target. This is mainly used for development.