Import qt4-gstreamer-0.10.2 as wip/qt4-gstreamer.

QtGStreamer is a set of libraries and plugins providing C++ bindings for
GStreamer with a Qt-style API plus some helper classes for integrating GStreamer
better in Qt applications.

Currently, it consists of the following parts:

* QtGLib - Library providing C++/Qt bindings for parts of the GLib and GObject
  APIs, a base on which QtGStreamer is built.
* QtGStreamer - Library providing C++/Qt bindings for GStreamer
* QtGStreamerUi - Library providing integration with QtGui.
* QtGStreamerUtils - Library providing some high level utility classes.

In addition, it provides GStreamer elements for drawing video on widgets,
graphics items and QML items.

This is the Qt4 version of qt-gstreamer.
+qt4-gstreamer
Bump version 20.0.1 to 21.0
commit message for above bumping will be on COMMIT_MSG.
Verified only on NetBSD/amd64 6.1_RC2 yet.