* Updated php.net link for some MemCache properties [skip ci]
* Changed protocol to https for links to php.net in comments
* Changed protocol to https for links to php.net in code
* Changed www.php.net (http) to secure.php.net (https) in comments
* Changed www.php.net (http) to secure.php.net (https) in code
* Changed protocol to https for links to php.net in UPGRADE.md
* Changed protocol to https for links to pecl.php.net in comments
* Changed us.php.net to secure.php.net (https) in comments
* Changed protocol to https for links to php.net in docs
* Changed www.php.net (http) to secure.php.net (https) in docs
* Changed protocol to https for links to pecl.php.net in docs
* Changed ru/jp.php.net to secure.php.net (https) in docs
Don't sure about russian guide: is this links meant to be for guide on russian, or not?
1. UploadedFile::getInstances($model, 'file'); sees only one file if not set ```'file[]'```
```php
<?= $form->field($model, 'file[]')->fileInput(['multiple' => '']) ?>
```
2. ```$form->errorSummary(..)``` not return all errors of file attribute, but only the last.
So I had to invent.
```php
if ($model->hasErrors()) {
echo '<pre>';
print_r($model->getErrors());
echo '</pre>';
}
```
So it should be?