Removed unnecessary PHPDoc property (https://github.com/yiisoft/yii2/commit/ce04134db24d3bcdc0388f5b7832dd1dbb1945ef)

Changed csrf-var to csrf-param due to meta validation error. The validation error as mentioned in the issue https://github.com/yiisoft/yii2/issues/2363. It is fixed in this pull request.

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

This reverts commit 80be824f.

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

fixes #1842

realpath(false) = current working directory.
This can cause problems with getAlias() which returns false.

see yiisoft/yii#3113

Added `yii\web\Request::get($name = null, $defaultValue = null)` and `yii\web\Request::post($name = null, $defaultValue = null)`

fixes #2093

issue #2093

fixes #2132, fixes #2133