Adding support for xsane

[Alexandre Prokoudine]

On 2/15/10, Richard Hughes wrote:

> Ideally we would talk to easy-scan / gnome-scan in the future using a
> nice DBus interface, but I think that's a few years away.

Robert Ancell blogged recently that he is going to implement color
management after 1.0, and his is now in post 0.9.0 bugfixing mode. So
it's probably not that bad :)

Alexandre