added a fallback for handling all request types

fixes #2066, related to #2043

Merge PR #2066 branch '2043-add-support-for-custom-request-parsers' of https://github.com/danschmidt5189/yii2

* '2043-add-support-for-custom-request-parsers' of https://github.com/danschmidt5189/yii2:
  Fixed type in JsonParser
  Tabs vs. spaces
  Added support for custom web\Request parsers (#2043)
  Adds customizable parsing functionality to the web\Request class (Issue #2043)

added support to parse json request to Request::getRestParams()

Fixes #2063: Removed `yii\web\Request::acceptTypes` and renamed `yii\web\Request::acceptedContentTypes` to `acceptableContentTypes`.
Renamed `yii\web\Request::acceptedLanguages` to `acceptableLanguages`

Some codestyle fixes

AutoTimestamp field renaming

Feature fixture

Removing `abstract` in Module