add xattr-install ebuild

Signed-off-by: Gregory M. Tuner <gmt@be-evil.net>
sys-apps/portage: clone upstream 9999 ebuild

Signed-off-by: Gregory M. Tuner <gmt@be-evil.net>
bump xattr-install and portage versions

Signed-off-by: Gregory M. Tuner <gmt@be-evil.net>
xattr-install: revbump

Signed-off-by: Gregory M. Tuner <gmt@be-evil.net>
portage: only require xattr-install if use xattr

Signed-off-by: Gregory M. Tuner <gmt@be-evil.net>