close #5355

fixes #3381

fixes #5339

Fixes #5232 and #5231

as discussed before, better do this change before RC to avoid breaking BC in GA.

fixes #5155

fixes #5147

- use default application formatting for the date value
- auto adjust to application language and format setting changes
- be consistent with formatter and date validator

fixes #1551

Fixes #5143: yii\bootstrap\ActiveField::label() should not encode label if it is explicitly specified. [skip ci]

feature is not reliable

fixes #5136

asArray will not include null valued keys

fixes #1311

Fixes #5126

- in composer the `~` operator is just a shortcut for `~1.0` = `>=1.0.0,<2.0.0`
  it does not prevent dev versions to be installed but neither does `1.*`
- dev versions are constrolled via `minimum-stability` setting and the
  `@dev`, `@beta`, `@stable`,... settings.
- setting bower packages that ship compiled files only with the stable
  release to use `@stable` in composer.json of the applictaions. This
  setting can be removed when we remove the `minimum-stability=dev`
  setting after GA.

fixes #5104, fixes #5101

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