Docstring keywords: required, body, file, overwrite

The keyword *[body]* marks the parameter type as body. This generates a textarea that is sent as the message body.
The keyword *[required]* marks the query string argument as required.
The keyword *[overwrite]* overwrites all other parameter types - only the one in the docstring are used.

Example usage:
 ```python
class PlacesPrefetchRequest(APIView):
    """
    Returns communities near your location
    [overwrite]
    Request Body -- Places as JSON [required] [body]
    """
 
```

I added [file] as a keyword to the docstring, which tells swagger that a multipart file should be uploaded.

 ```python
class ProfilePictureView(APIView):
    """
    Multipart -- Image [required] [file]
    """
    parser_classes = (MultiPartParser,)
    
    def put(self, request, *args, **kwargs):
        files = request.FILES
        print "files", files
        return Response({})
 ```