This introduces LocalDataQuerySet, which operates similarly to a

QuerySet, but can store any iterable data. The interface it exposes is

similar enough to QuerySet for basic usage.
While this may be useful for various purposes, it's largely intended for

use with WebAPIResource. Before now, getting WebAPIResource to return

data not from a database was tricky. You had to rewrite the

serialization functions, get(), get_list(), etc. Now, get_queryset() can

return a LocalDataQuerySet, passing in whatever it needs, and

WebAPIResource will work with it.

Unit tests pass.
Used this with the new HostingServiceResource to great success.