Misc changes to reduce image size.

1- Stop generating locale via dracut; generate choosen locale at build time.
2- Stop generating a local repository (/packages) to the rootfs.
3- Drop support for -l option.
4- There's no need to copy kernel modules manually anymore.
5- Switch to base-system and some more additional packages to drop base-system-live
   requirement.

WIP! the installer must be updated to copy rootfs files to the targetdir.