WIP: Convert into restface backend handler
Add notes about HTTP transactions / using buckets for metadata
First working version

* Now loads as a restface handler
* Responds to simple GET requests
Fix POST code path

Try with:
 curl -v -X POST -d "_timestamp=`date -Iseconds`&_rev=1234&wikitext=some wikitext `date -Iseconds`" \
 http://localhost:8888/v1/en.wikipedia.org/pages/Foo/rev/

Also some minor clean-up.
More clean-up