Revision 803245

Initial commit of _update handler. Thanks to Paul Davis, Jason Davies for code and others for discussion.

The _update handler accepts POSTs to paths like: /db/_design/foo/_update/bar and PUTs which include docids, like: /db/_design/foo/_update/bar/docid

The function signature:

function(doc, req) {
  doc.a_new_field = req.query.something;
  return [doc, "<h1>added something to your doc</h1>"];
}

The tests in update_documents.js are fairly complete and include examples of bumping a counter, changing only a single field, parsing from (and returning) XML, and creating new documents.