fixes #2220

issue #1797

Fix URL Bootstrap

Update security.md

Documentation edits

Improved `QueryBuilder::buildLimit()` to support big numbers

Revert "Fixes #1856: The default CSS class for hint generated by `ActiveField` is changed to `help-block`"

This reverts commit 7ae4695d.

Fixes #2212: `yii\gridview\DataColumn` generates incorrect labels when used with nosql DB and there is no data

added quick and dirty code highlighing and got much faster

Latvian translation

Update url.md

Fixes #706: Added `yii\widgets\Pjax` and enhanced `GridView` to work with `Pjax` to support AJAX-update

Documentation updates