@toslan can you have a look into the CS?

FILE: /home/travis/build/joomla/joomla-cms/modules/mod_languages/helper.php
--------------------------------------------------------------------------------
FOUND 4 ERROR(S) AFFECTING 3 LINE(S)
--------------------------------------------------------------------------------
 103 | ERROR | Opening parenthesis of a multi-line function call must be the
     |       | last content on the line
 103 | ERROR | Whitespace found at end of line
 104 | ERROR | Whitespace found at end of line
 105 | ERROR | Closing parenthesis of a multi-line function call must be on a
     |       | line by itself
-------------------------------------------------------------------------------

This does not work.
I may get some urls of type:
http://localhost:8888/testwindows/trunkgitnew/en/multi-lingual-steps-by-steps.html?id=31:enable-the-language-filter-system-plug-in
instead of
http://localhost:8888/testwindows/trunkgitnew/multi-lingual-steps-by-steps/31-enable-the-language-filter-system-plug-in.html
which evidently gives a 404.

@infograf768 There is no language section (like '/en/' )In your desired url which appears on all paths of multilanguage site. Something wrong with the structure of menus?

It has been over 1 year since the last comment here and based on comments above I am closing this at this time.