GeoSites update

[dave <davidr sucs org>]

Hi all,

I've rejiggled the geosites updates as per Edd's suggestions. No new
functionality; the main change is the introduction of a Locale class
(and subclasses) which represent a place, and contain at least a
city,region,country. This is used by e.g. the GeoSites backend.

I've incorporated Clement's fix for US two-letter state codes (but I've
moved it into the Locale class, since it might be generally useful to
code that is interested in Locales).

Finally, the GeoSites backend now chains placenames (as keywords). I
think we ought to introduce a "place" cluetype for this kind of thing;
nothing else is exactly appropriate.

Feedback appreciated. My next plan is to do some work on the renderer
(currently there doesn't seem to be one). Edd, do you have any
suggestions (or code - I believe you had this going at one stage) for
this one? Ideas welcome.

The patches are available at http://www.cs.swan.ac.uk/~csdave/dashboard/
(they're a bit too big to post here).

dave