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Fixes #3443: Fixed `yii\bootstrap\Nav` and `yii\bootstrap\Dropdown` were generating wrong ids for submenus

fixes #4343

reverts 45e4973a

Fixes #4318: `yii\helpers\Html::ul()` and `ol()` will return an empty list tag if an empty item array is given

absolute auth timeout

Conflicts:
	framework/CHANGELOG.md

fixed outdated example.

This is based on the code from Yii 1.1.14 by Ivo Kund.

Fixes #4324: removed old way of developing Yii from the docs since app/link is much better/simpler workflow

Fixes #4184: mentioned a safer way of using dummy cache that works in case of merging configs of advanced app

Fix typo on elasticsearch readme file

Fixes #4051: Renamed `yii\caching\GroupDependency` to `TagDependency` and added support for associating multiple tags to a single cached data item

Remove extra import and fix comment