Building parameters from filtering fields when field is not using ALL or ALL_WITH_RELATIONS, fails when a tuple is used instead of a list

A resource with this filtering attribute, is valid for tastypie:

```python
       filtering = {
            "session_number": ('exact',),
            "number": ('exact',),
            "member": ('exact', ),
            "date": ALL
        }
```

But the mapper fails building those fields because is expecting the value ALL, ALL_WITH_RELATIONS or a list type. 

`is_sequence` will check for any valid sequence type.