xfce4-mixer does not store controls

[schnitzeltony]

Seems something has changed in xfconf. Running xfce4-mixer from console says:

(xfce4-mixer:883): xfconf-common-WARNING **: 00:07:48.621: GType GPtrArray_GValue_ doesn't map to an Xfconf type

(xfce4-mixer:883): xfconf-common-WARNING **: 00:07:48.622: Unable to convert GType '(null)' to GVariant

[schnitzeltony]

And we need

• GTK3 port - once xfce 4.16 comes up
• should get rid of gstreamer 0.1 by direct alsa access