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)
For example, if I do
```
allow(Yast::SCR).to receive(:Read).with(@yast2_path, anything) { whatever }
```
Without this (almost) explicit
```
allow(Yast::SCR).to receive(:Read).and_call_orignal
```
any call to SCR.Read will throw errors like this
```
Received :Read with unexpected arguments
    expected: (#<Yast::Path:0x00000001e70300 @components=["target", "yast2"]>, #<...AnyArgMatcher...>)
    got: (#<Yast::Path:0x00000002fd3b10 @components=["probe", "keyboard", "manual"]>)
```
And, of course, I don't want to explicitly allow all the possible calls to Read just to override a few