Add rest-rate-limiting.md to translate into Russian
Translated rest-rate-limiting.md into Russian
Fixed translation of 'Rate Limiting' in README and related sections
Fixes #4708
Fixes #4697: MSSQL query builder does not work for newer MSSQL versions when LIMIT is used without ORDER BY
Add rest-error-handling.md to translate into Russian
Translated rest-error-handling.md into Russian
Merge pull request #4699 from bevalorous/docs-guide-russian-translation

Translated rest-rate-limiting.md and rest-error-handling into Russian [skip ci]
Fix for #4372
Doc update [skip ci]
Changelog update [skip ci]
Merge with master
Update .gitignore
Update .gitignore
Fixes #4636: Added `yii\web\Response::setDownloadHeaders()`
Fixes #4501: Renamed the constant `YII_PATH` to `YII2_PATH`
added bower.json for yii2-framework. [skip ci]
updated ignore. [skip ci]
adjust bower.json further [skip ci]
do not export mailer in BaseMailerTest message

fixes test break in HHVM due to export of a closure