Revert "Replace global user functions with WT_User class" - submitted to wrong branch

This reverts commit 04e895d26b4a0f606b8f83488ecb32127df081cf.
#1316253 - Interactive tree error
Updated danish translation by Jamie Jaconelli
Colorbox titles not rendered correctly on RTL
Remove webkit-transition, causing problems in Chrome browser
#142 - Misformed nofollow attribute
DocBlock headers - fix mismatches with code and apply consistent formatting
Update lt.po

Mainly fix up the different versions of " and some translation updates
Merge pull request #143 from vytux-com/patch-6

Update lt.po
Added missing translation, some fixes
Merge pull request #144 from Art4/patch-1

Added missing translation, some fixes
CSS typo
Undefined variables error in import wizard
Refactor global user functions into new User/Auth classes
Hard-coded table prefix
Remove unused code
Conflict in variable names
Error handling logic in login.php
Create separate route for logout
New User class breaks changes log #145