- Properties data, xreal, yreal, ... to GwyDataField.
- GwyContainer subclass.
- Docstrings for gwyfile.objects.
- gwyfile.load convenience method for loading files.
- Removed imports of classes from gwyfile.objects to gwyfile.
- Removed GwyDataField.get_data(). Dropped in favor of properties.
- GwyObject.fromfile and GwyObject.tofile now also take file-like objects.
- Initial version with basic functionality. No public release.