Martin Allison

I.e. don't assume that every filter is just of the form `"%s (=|=|:) %s"` because this won't work for the search API's 'distance' queries on `GeoFields`

Using `field.to_search_value(value)` for converting values passed to `.filter()` because the value indexed by the search API isn't always the same as the value you'd use to filter that field. Dates...

Move away from using `__getattribute__` and `__setattr__` on `DocumentModel` instances and instead use `__get__` and `__set__` to do the same job on `Field` instances.

In particular: - inheritance of `DocumentModel` - `ids_only=True` works with `search` and `list_indexes` - indexed text fields - unicode stuff - cursor stuff

In particular: - unicode acceptance - and-/or-/not-ing `Q`s works as expected - keyword cleaning - invalid filtering values - empty filtering/keyword values