If raw responses are disabled, document's 'json' field gets cached rather than the whole document

[shb]

When raw responses are disabled, and a document retrieved from the db contains a field named json, its value will overwrite that of the Response.json (which should be a reference the whole original document). Since the latter is accessed to save the document in cache (lib/cradle/database/documents.js:44):

if (! err) that.cache.save(res.id, res.json);

the result is that only that one document field will get cached rather then the whole document, breaking the application in an obscure way.