Fixes #6852: Added `yii\helpers\BaseHtmlPurifier::helpers()` in order to be able to configure `HtmlPurifier` helper globally via subclassing

Fixes #6969: `yii\helpers\ArrayHelper::htmlEncode()` and `htmlDecode()` should not remove non-string data

Fixes #6697: Added `yii\helpers\Url::current()` method that allows adding or removing parameters from current URL

Fixes #6207: Added support for truncating HTML strings using `StringHelper::truncate()` and `StringHelper::truncateWords()`

new private method `truncateHtml` now used by `truncate` and `truncateWords`

Some Annotation Typos

close #6029

Recursive method call must have the same parameters as the first call.

Just a readme update.
"If you do not want any hidden input, you should explicitly set this option as null."

close #5823

Fixes #4457: Added support for using noscript for css files registered through asset bundles and Html helper

Fixes #5587: `json_encode` is now used with `JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE` where it makes sense, also it is now default for `Json::encode()`

API is not finished.

issue #5082

Fixes #5316: Added `startsWith()` and `endsWith()` to `yii\helpers\StringHelper`. Methods are binary-safe, multibyte-safe and optionally case-insensitive

Fixes #5058: `yii\helpers\Html::activeCheckbox()` and `activeRadio()` will generate labels by default using the corresponding attribute labels

adding and reworking the conversion of:
- ICU to PHP
- PHP to ICU
- ICU to JUI
- PHP to JUI