Allow custom GStreamer elements to be used as a video sinks.

Change-Id: I91b489adb92d69d7edc8e8c745fb0d1c23a2e891
[packaging] Properly enable multicore builds
Merge pull request #1 from rburchell/master

[packaging] Properly enable multicore builds
Allow the camera source to be overridden with an environment variable.

And only intervene in caps negotiation when specific values have been
set, otherwise we're just as likely to create a caps filter which
prevents the pipeline being setup as resolve indecision between src
and sink elements.
Fix playback with exotic decoders.

Allow overriding of flags, and extend VAAPI hack to additional formats.
Merge pull request #2 from adenexter/gstreamercontrol

[qtmultimedia] Enable the use of non-standard gstreamer cameras, and video sinks.
[qtmultimedia] Enable resource policy support.

We were missing a build dep, and our resource policy port uses a different .pc.
[qtmultimedia] Change some more libresourceqt1 => libresourceqt5
Merge pull request #3 from rburchell/master

[qtmultimedia] Enable resource policy support.
Merge pull request #4 from rburchell/master

[qtmultimedia] Change some more libresourceqt1 => libresourceqt5
Implement resource policy plugin using libresourceqt.

This contains a new resource policy plugin, replacing the built-in
code that was deleted when the plugin interface was removed in
138242fb2dc19438a0ead34b36af848800e27190 (which unfortunately did not provide a
plugin).

Change-Id: Iae7ed6edc330c69ca0c72d50bde6c7e12b8cca4e
[packaging] Add plugin-resourcepolicy-resourceqt for libresource based resource policy

Signed-off-by: Carsten Munk <carsten.munk@jollamobile.com>