work on a WebKit based browser for the XO

requires pywebkitgtk, gnome-python2-gconf and WebKit-gtk:
sudo yum install pywebkitgtk WebKit-gtk gnome-python2-gconf
(maybe I can wrap this into the ./setup.py dist_xo packaging step.)

The code for downloading just got merged into webkit (r41401), probably
need to update the pywebkitgtk bindings to be able to download things