Comment # 7 on bug 1086036 from Dominique Leuenberger

Discussed with sbrabec on IRC, the agreed path forward should be:

* unconditionally enable t-u-u again in all packages
  * on Tumbleweed, translation-update and translation-update-upstream are
placeholder packages without content (stale content was what lead to strange
translations in the past, which triggered the disabling of for oS)

* Leap and SLE being in sync, can share the t-u and t-u-u packages

* For Leap there is the risk that some packages handled by t-u (post install
updates) differ between SLE and Leap; those might need extra care