Fixed indentation.
Refactoring fix for bnc#476490
Fixed indentation, removed dead code and useless comments
Straightened dialog sequence for s390 Add/Eddit actions on interfaces

It also reimplements fix for bnc#476490.
Select reasonable defaults for s390 device variables. See bnc#747844
Replaced usage of LanItems::current by getter at couple places.
Fixed indentation and formating
Updated changelog.