toolbar UI updates

Revert "Added `yii\base\Module::getParam($name, $defaultValue = null)`  to conveniently work with application parameters"

This reverts commit 3b95aa9c.

Improvements in exhibition of the changed files in Gii.

Added `yii\base\Module::getParam($name, $defaultValue = null)`  to conveniently work with application parameters

Moved most of the user-related logic into form models

fixed i18n link

Adding support for the X-HTTP-Method-Override header

This reverts commit 80be824f.