* Added support for nested, flattened fields.
* Added support for dotted-names in field names.
* Added support for dotted-names in `model_attribute`.
* Added `GISSERVER_WRAP_FILTER_DB_ERRORS` setting for debugging filter errors.
* Added API's for easier subclassing:
* `FeatureField.xsd_element_class`.
* `FeatureField.parent` for elements in a complex feature.
* `gisserver.features.get_basic_field_type()`.
* Fixed CSV output to render datetimes as UTC, identical to GeoJSON
* Fixed bugs found by CITE compliance testing:
* Fixed support for LIKE operators on string-based foreign keys.
* Fixed `<fes:PropertyIsLike>` on numeric values, when the field is a string.
* Fixed comparison of `<fes:PropertyIs..>` when the field name and value are reversed.
* Improved error messages when using invalid comparison operators.
* Optimize feature retrieval, only fetch the actual fields being displayed.
* Compactified XML output headers.