Implements geospatial filter support.
Implements geospatial filter support.

You can now define a `GeometryFilter` on FilterSet and use any of the
provided lookup types to do geospatial lookups.

The usage of LOOKUP_TYPES in __new__ is for compatability with
https://github.com/philipn/django-rest-framework-chain and
`AllLookupsFilter`

pglotov/django-rest-framework-gis,bopo/django-rest-framework-gis,djangonauts/django-rest-framework-gis,nmandery/django-rest-framework-gis,nmandery/django-rest-framework-gis,barseghyanartur/django-rest-framework-gis,illing2005/django-rest-framework-gis,arjenvrielink/django-rest-framework-gis,manhg/django-rest-framework-gis,sh4wn/django-rest-framework-gis