You best NOT use the things in there, it is just meant as describing the method (find out what settings and where..)
I have created English and Lithuanian files and put them in languages folders.
Why ? English is complete (default in each package and should be fully present), and Lithuanian ( i know there's a 1.0.4 version out there; and maybe errors in it, but even if LAN is displayed.. it is workable..(ok not the nicest,but 1 step at a time, else you get distracted from the goal.. As long as LT is not up to v2 the old one has to do for time present.
The code you posted for userclass is advanced (a special thing). Please forget that, it wil take you nowhere.(please remember as i posted, it is older and intended as info in general.)
For the posts concerning English custom en Lithuanian custom... please ALSO forget that.It has already been incorporated in the language structure. Those so called custom files are basically the main language files like (see the languagefolders) English.php and/or Lithuanian.php etc... You do not have to create a single file as described in that tut.Only the method counts (a pdf reader with pagecount > pages 4,5,6 ) It does show you what to copy (what you need from main site language).eg Pages or News etc..
I am close to finish the new tutorial up to a point that you can use to get first results; make a split there and keep expanding.Just hold a little longer.. (please do re-read the posts, some things would make more sense/understandable now, since you were a little busy already...