Remove check for `FileField`; it doesn't exist
Fix a couple of warnings
Clarify a couple of comments, remove a trailing ;
Simplify callbacks. Everything gets a list; no more split _single and _list variants.
`put_list`: do pick up returned bundles when saving
Move callbacks for serialize/deserialize into their respective container methods
Add `request` param to (de)hydrate/(de)serialize
Paginator: replace `len` on queryset (builds a document for each result) with `count`. Looks like a huge time saver in some quick tests!
Prefetch documents; improves get_list performance. Closes #478 on PP.