formatting date and time values for years >=2038 or <=1901 is now possible also with intl extension is
installed. 32bit systems will fall back to the PHP implementation because intl uses a 32bit UNIX timestamp internally.
On a 64bit system the intl formatter is used in all cases if installed.

fixes #5577

Added content to give a clear example to those that don't intuitively know how to set the template property using array notation.

close #6811

fixes #6748

allows using logger without a Yii application now.

close #6739

close #6779

Fixes #6398: Added support for specifying dependent component in terms of a configuration array for classes such as `DbCache`

to Active Field

fixes #6734

added tajik language

added tajik translation

`Content-Transfer-Encoding` is not a valid HTTP header (cf [RFC 7230, section 3.3.1](http://tools.ietf.org/html/rfc7230#section-3.3.1), [RFC 7231, section 8.3](http://tools.ietf.org/html/rfc7231#section-8.3), [IANA Message Header Registry](http://www.iana.org/assignments/message-headers/message-headers.xhtml)). The correct HTTP pendant would be `Transfer-Encoding: identity`, which were entirely bogus.

fixes #6717

- yii\db\BaseActiveRecord::findByCondition better exception
- yii\db\ActiveRecord::findByCondition better exception

close #6704

fixes #6691

Fixes #6678: `yii\behaviors\SluggableBehavior` will generate a new slug only when the slug attribute is empty or the source attribute is changed

Fixes #6589: updated code style guide to mention else after return, adjusted code involved in the issue

Fixes #6632: `yii\di\Container::get()` did not handle config parameter correctly when it is passed as a constructor parameter