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)
constant. Better to have 
```
module SCRStub
  YAST_PATH = Yast::Path.new(".target.yast2")
  YCP_PATH = Yast::Path.new(".target.ycp")
  SIZE_PATH = Yast::Path.new(".target.size")
```