Tar could not handle the headers.

This reverts parts of commit 8b1a5301.
Keep the usage fixes.

and install scripts should not be in $source

and relocate the place of the symlink in tar header, as symlink
use the linkname field. now it's split to devmajor, devminor and
padding fields.

we want the sysklogd on the iso

init will only autoadd those when booting

This is needed when bootstrapping the system.

This solves issues for rsync jobs for mirrors.

So basicly, running 'abuild-keygen -a -i' will be all you need to do to
be able to use abuild-sign and install the signed packages.

we can only sign indexes so far