new: x11/xfce4/adwaita-xfce-icon-theme

x11/gnome/adwaita-icon-theme contains the Hidden=true attribute in its 
index.theme file, for reasons attibutable to the upstream Gnome Project.

This means that Adwaita does not appear as an 'Icon Theme' choice in 
non-gnome desktops such as Xfce in the Settings/Appearance dialog.

Non-desktop x11 systems are also affected.

On non-Gnome systems if applications use the Adwaita 'symbolic' icons 
(for exmaple) those icons will not appear.

The attached port x11/xfce4/adwaita-xfce-icon-theme depends on 
x11/gnome/adwaita-icon-theme and adds some other icons used by Xfce.

It installs to /usr/local/share/icons/adwaita-xfce and has Hidden=false 
in its index.theme

I am unsure whether this should be in x11/ or x11/xfce4 category. Advice 
please.

Comments/testing?

Chris