README: Update for Dizzy release

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
README: Update branches to master for development

This reverts commit 7a9ba77d90e7f242eb8f3e7e7df697c79ed9ce59.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
fsl-image-machine-test: Add Gstreamer 1.0 package groups

This includes:

* packagegroup-fslc-gstreamer1.0
* packagegroup-fslc-gstreamer1.0-full

In the image.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
fsl-image-multimedia: Add Gstreamer 1.0 package groups

This includes:

* packagegroup-fslc-gstreamer1.0, in fsl-image-multimedia
* packagegroup-fslc-gstreamer1.0-full, in fsl-image-multimedia-full

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>