Fixes #4823 and #6005: `yii message` accuracy and error handling were improved by using PHP tokenizer instead of regular expressions. Removed eval() as well.

fixes #5683

Fixes #4643: Extra options specified in `yii\widgets\Breadcrumbs::links` will be treated as HTML attributes for the generated hyperlinks

return value would not be a valid array when json encoded after unlink().

fixes #6065

fixes #4745

Fixed `yii\sphinx\QueryBuilder` does not support comparison operators (>,<,>= etc) in where specification

fixes #5652

fixes #5601

also enhance test README

Fixed `yii\console\controllers\AssetController` breaks CSS URLs in case target file localed at `yii\web\AssetManager::basePath` root

Fixes #5467: Added ability to pass HTML tag options to `asEmail()`, `asImage()` and `asUrl()` methods of `yii\i18n\Formatter`

Additional check added to `yiiunit\extensions\authclient\BaseClientTest::testNormalizeUserAttributes()`

Added ability to operate nested and complex attributes via `yii\authclient\BaseClient::normalizeUserAttributeMap`