create the *-promo files in `rake tarball`
switch to skelcd-control-openSUSE-LangAddOn package
Merge pull request #1 from yast/switch_to_addon

Switch to skelcd-control-openSUSE-LangAddOn
removed -promo handling (leftover copy from the openSUSE skelcd)
Merge pull request #2 from yast/build_fixes

Switch to lang add-on