typo fix

The scripts in asset bundles are now registered in `View` at the end of `endBody()`. It was done in `endPage()` previously

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

This reverts commit 3b95aa9c.

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

This reverts commit 80be824f.

Fixes #1812: Hide potential warning message due to race condition occurring to `Session::regenerateID()` call

Fixes #2298: Fixed the bug that Gii controller generator did not allow digit in the controller ID (qiangxue)

Fixes #2303: Fixed the bug that `yii\base\Theme::pathMap` did not support dynamic update with path aliases