Fixes #6398: Added support for specifying dependent component in terms of a configuration array for classes such as `DbCache`

fixes #6717

Fixes #6632: `yii\di\Container::get()` did not handle config parameter correctly when it is passed as a constructor parameter

Fixes #5494: Added support for specifying a menu header as a configuration array in `yii\bootstrap\Dropdown`

fixes #5503

fixes #6263 and has no problem with PHP Bug:

> it is a PHP bug: https://bugs.php.net/bug.php?id=45543
> Fixed in this commit: php/php-src@22dba2f#diff-7b738accc3d60f74c259da18588ddc5dL2996
>
> Fixed in PHP >5.4.26 and >5.5.10. http://3v4l.org/mlZX7

Fixes #5627: Added `yii cache/flush-schema` console command to flush DB schema cache of a given database connection

fixes #5448

fixes #6164

Fixes #4823 and #6005: `yii message` accuracy and error handling were improved by using PHP tokenizer instead of regular expressions. Removed eval() as well.

fixes #5683

Fixes #4643: Extra options specified in `yii\widgets\Breadcrumbs::links` will be treated as HTML attributes for the generated hyperlinks

fixes #5652

fixes #5601