- Chg: `getComponent()` and `setComponent()` in `Application` and `Module` are renamed to `get()` and `set()` respectively. (qiangxue)
- Chg: The signature of `Yii::createObject()` is changed. Constructor parameters must be passed as the second parameter. (qiangxue)
- Chg: `Yii::$objectConfig` is removed. You should use `Yii::$container->set()` to configure default settings of classes. (qiangxue)
- Chg: Removed `yii\grid\Column::getDataCellContent()` and renamed `yii\grid\DataColumn::getDataCellContent()` to `yii\grid\DataColumn::getDataCellValue()` (cebe)