fixes #3587

issue #3520

breaking changes.

better not delete all to avoid data loss

pr #2324

```
$result = Article::find()->query(["field" => ["title" => "yii"]])->all();
````

fixes #1993

meet the AR interface requirements.

now supports mapped primary key when _id is part of source with an
alias.

issue #1313

issue #1317

far better than depending on fat guzzle