* Ragazzo-partial-response-enh:
  refactored web/Response::sendFile()
  Display Name of HttpException instead of classname
  string helper fixed, mime-type reverted
  code style fix
  partial response added, new code-style applied

- better throw http exception on not satisfiable range request
- constitent header names
- fixed range end when range request is to the end
- added unit test

related to #275, fixes #148

class name is alwarys HttpException, better display the name of the http
error.

Fixes #143. UrlValidator and EmailValidator IDN support.

Form asset bundle registering code moved from ActiveForm::run() to the *Validator::clientValidateAttribute().

punycode.js asset bundle registering moved from ActiveField to validators.

Make multisort compatible with Sort

Merge PR #275 branch 'partial-response-enh' of https://github.com/Ragazzo/yii2 into Ragazzo-partial-response-enh

* 'partial-response-enh' of https://github.com/Ragazzo/yii2:
  string helper fixed, mime-type reverted
  code style fix
  partial response added, new code-style applied

Test code
```php
$orders = $this->getSort()->getOrders();
ArrayHelper::multisort($data, array_keys($orders), array_values($orders));
```

Fixed issue with getting Object component

Fixes #226: atomic operations and transaction support in AR.