Log Message:
qt5-qtwebkit: Update to 5.212.0-alpha4

WARNING: This release is based on old WebKit revision with known unpatched \ 
vulnerabilities. Please use it carefully and avoid visiting untrusted websites \ 
and using it for transmission of sensitive data. Please wait for new release \ 
from qtwebkit-dev branch to use it with untrusted content.

### New APIs

* `QWebSetting::ErrorPageEnabled` - `true` by default, allows to disable \ 
built-in error pages if they are not desirable

### Improvements

* [CSS Compositing](https://www.w3.org/TR/compositing-1) is now supported
* Push is enabled by default for HTTP/2 requests
* QtWebKit does not require Python 2 anymore for building and can use Python 3 \ 
instead
* QtWebKit won't be eager to pick bitmap fonts as a suitable choice for standard \ 
font families
* More appropriiate hinting option for web fonts is used

### Bug fixes

* Fix memory leak in \ 
[CustomEvent](https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent)
* SVG fragment identifier is not respected if it is a part of an HTTP URL  (#818)
* Context menu actions for images in Resources tab of inspector use blob: \ 
instead of original URL (#899)
* Always enable JavaScript for QWebInspector (#566)
* Inspector UI: Only selected item is painted in Styles combobox (#262)
* Inspector should inspect itself in DEVELOPER_MODE only (#444)
* fast/gradients/css3-color-stop-invalid.html - box is green instead of white (#230)
* Work around [QTBUG-77308](https://bugreports.qt.io/browse/QTBUG-77308) when \ 
using Qt < 5.14
* Fix compilation errors with ICU 65.1 and Qt 5.14
* Fix compilation when QPdf is disabled in Qt
* Fix compilation with MinGW for x86_64 target

### Third-party software updates

Windows binaries are shipped with `ICU 65.1`, `libxml2 2.9.10`, `libxslt \ 
1.1.34`, and `libjpeg-turbo 2.0.3`.

## Sponsors

This release is sponsored by:
* dizmo AG
* Florian Apolloner
* Movable Ink and Michael Nutt
* ScrapingHub