task-self-hosted: add hicolor-icon-theme and socat

task-self-hosted: add hicolor-icon-theme and socat

python-pygtk depends on libgtk and libgtk's recommends have
gdk-pixbuf-loader-{png,jpeg,gif,xpm}, so we have the warnings.
We can add hicolor-icon-theme to fix the warning:
Configuring gdk-pixbuf-loader-png.
gtk-update-icon-cache: No theme index file.
Configuring gdk-pixbuf-loader-jpeg.
gtk-update-icon-cache: No theme index file.
Configuring liberation-fonts.
Configuring gdk-pixbuf-loader-xpm.
gtk-update-icon-cache: No theme index file.
Configuring gdk-pixbuf-loader-gif.
gtk-update-icon-cache: No theme index file.

Add socat for to faciliate proxy setting.

(From OE-Core rev: d32933a74b380aac906bbfbe1ec7d89b02e9f72d)

Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>