Fixes #4586: Signed bigint and unsigned int will be converted into integers when they are loaded from DB by AR

also fixed an issue with default value loading of bool columns.

fixes #3489, fixes #4085, fixes #3920
related to #4672

fixes #4654

`$config` can now be a closure that will have the `$configInstance` passed as the first param.

updated docs.

close #4656

Fixes #4122: `Html::error()` and `Html::errorSummary()` are now accepting `encode` option. If set to false it prevents encoding of error messages

- can be used to enable caching in a request without the need for any storage
- useful for example in complex console tasks that should still be independed

Fixes #4371: Active form client validation wasn't working in case of two models having same named fields

When rendering multiple models in the same ActiveForm if any of the field names in the two models is the same then the corresponding attribute in the yiiActiveForm object in yiiActiveForm.js (ie $('form').data('yiiActiveForm').attributes) of the first rendered model is overwritten by the attribute of the last model causing the client-side validation for the overwritten field not to run at all. Example: given two models Car and Owner with attributes {make, age} and {name, age} then if the Car is rendered first its age attribute will not have any client validation.

Fixes #4644: Added `\yii\db\Schema::createColumnSchema()` to be able to customize column schema used

Fixes #4597: `yii\composer\Installer::setPermission()` supports setting permission for both directories and files now (qiangxue)

Fixes #4592: Fixed `yii help` command was listing incorrect action names for methods like `actionSayNO`

fixes #4602, close #4624

Refactored `yii\web\User`.

- `beforeValidateAll`
- `afterValidateAll`

fixes #4234, close #4559

fix typo Markdown->GithubMarkdown in $flavors['gfm-comment']