Basic edits
minor doc fix. [skip ci]
Russian translation - semantic fix [skip_ci]

Example

```
['profit', 'number', 'min' => 0.01],
```

Value 0.01 is allowed
Check for UPLOAD_ERR_NO_FILE in UploadedFile

fixes #4276, close #4358
Merge pull request #4364 from SDKiller/patch-5

Russian translation - semantic fix [skip_ci]
`yii\web\Request::cookieValidationKey` is now automatically generated by the installation script for the basic and advanced application templates
Request::cookieValidationKey must be explicitly specified now.
Fixed test break.
Fixes #4362: Made carousel indicators optional
Fixed test break.
Fixes #4048: Added `init` event to `ActiveQuery` classes
Fixed test break.
Refactored code.
dropDownList encodeSpaces for subgroups

fixes #4105, close #4376
Added support for relation by array attributes

fixes #1249
added elasticsearch test case for array attribute relations
fixed issue with indexBy and array valued relations
Fixes #3611: Refactored query caching.
typo fix [skip ci]
Sphinx distributed indexes support provided