Regenerate initrd after configuring keyboard (bnc#888804)

* Some autotranslated code polishing (in a different commit for easier review)
* Update dependency on yast2 >= 3.1.94 (new messages)
yes, after clarifying I agree with `stub_presence_of`.
 about `stub_scr_write` I do not agree, as yast almost always read values before writting, so you need to somehow mock it and in such case it make sense to have prepared chroot with such file. I actually considering to have stub_scr_write only optional, as sometime you need for testing agents check really written value so you do not want to stub writting.