Assure that the language buttons in the display settings always
show the content and the UI language and that all the buttons are
filled with some language (by assuming major world languages if
nothing more likely was found).
Also other fixes:
* Add lang and dir attributes for the languages.
* General refactoring and better variable names.
Change-Id: Ie6a93439237b389179ebc6c4a5df34c1566a5e12
3699095401