Merge pull request #4317 from VesnaT/io_refactor

io: Refactor FileFormat

Author: janezd

Orange/data/__init__.py

@@ -6,5 +6,7 @@
 from .domain import *
 from .storage import *
 from .table import *
+from .io_base import *
+from .io_util import *
 from .io import *
 from .filter import *