Since the config was created in live, it remained after installation.
Now the config will be created at the first start of live and only
if /image/ALTLinux/ is present (it will not be available when
bootloading via http or ftp). After installing live, the package will
be deleted and the config will not be created at the first start.

We've got some parts of it in build-distro feature,
and some went to dev feature for no real reason.

But a bare installer might go without package base,
and LiveCDs other than live-builder might find local
repository useful given aufs2 root overlay.

Now the overall scheme is more straightforward:
- a distro:
  + asks that a package repo be included
  + cares to further add the packages to it
- a repo feature:
  + pulls in sub/main for it to happen
  + provides genbasedir script to create repo metadata
  + supplements live feature with repo configuration