[cairo] cairomm new_path / clear_path

[Jonathon Jongsma]

There's a function cairo_new_path() which has been wrapped in cairomm
as Context::clear_path().  As far as I can tell, this is just about
the only function whose name was changed from cairo to cairomm.  With
the addition of a new API cairo_new_sub_path (which I wrapped as
Context::new_sub_path), there's no longer an obvious correlation
between these functions in cairomm.  I would propose changing
clear_path() back to new_path().  Is anybody opposed to this?

cairomm has not been declared API stable yet, so I think we can get
away with changing it now, but we should do it soon if we want to do
it.
-- 
jonner