* Migration::upsert() returns void
* Unneeded `@property` tags
* Add missing `null` param/return types
* Null types for db\Query + db\ActiveQuery
* Fixed testSelect
* Null types for Validator
* Several more null types
* One more
* Make AccessRule::$allow always a boolean
It doesn't have any special null handling, so it's safe to default to false
* Validator::$skipOnEmpty is always a boolean
* Catch all throwable from Widget::widget()
* Don't limit $previous args to \Exception
The actual \Exception allows $previous to be any throwable in PHP 7+
* Add Throwable catch block to Instance::get()
* Throwable cleanup
Comment changes only.
- Document \Throwable instead of \Exception wherever appropriate
- Removed redundant exception/error classes when \Throwable is referenced
* Yii::setlogger() accepts null
* ArrayHelper::removeValue() can remove any type of value
* Change default $allow value to false
- Deprecated `yii\base\BaseObject::className()` in favor of native PHP syntax `::class`, which does not trigger autoloading
- Deprecated XCache and Zend data cache support as caching backends
- Deprecated `yii\BaseYii::powered()` method
- Added `yii\base\InvalidArgumentException` and deprecated `yii\base\InvalidParamException`
- Added `yii\BaseYii::debug()` and deprecated `yii\BaseYii::trace()`
