[open-literature] Open Letters work

[print.crimes]

Afternoon,

I've been working on the open letters code and have added / changed a bit.

I've added basic templating to the letters, created html indexes, 
created rdf versions of the letters, correspondents and an endpoint. The 
endpoint has been validated against the W3 rdf validator but work 
remains to be done on url rewriting to tidy the urls up (the validator 
doesn't appear to have an issue with the current ones but it would be 
good to tidy them up). I've hidden the timeline until it is written, 
added a page for the schema for the purl link to refer to.

I've registered http://purl.org/letter which currently points to the 
opencorrespondence.org site (until the latest changes go live and I'll 
alter it to point to the correct page).

I still need to write a "get-involved" page, tidy up the parser 
(especially for the textReferred elements) and do the url rewrites but 
hopefully the project should now have enough for some experimentation 
when its downloaded and run. The PHP end point will be updated in due 
course.

Rufus: can you update the current site with this version? Its a little 
less "interimy".

All best,
Iain