GStreamer version can now be changed using a DISTRO_FEATURE:
'gstreamer010' for GStreamer 0.10 and 'gstreamer' for GStreamer 1.0

This can also be used to remove all gstreamer packages from image
and toolchain.

Default version is still the old 0.10

Change-Id: I54b19962ccd0dfd2f71bb44e231bf5af43ccfab9
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@theqtcompany.com>