added FormatError to convenience imports of package util

QtPyLoT.py

@@ -36,6 +36,7 @@ from pylot.core.read import (Data,
 from pylot.core.util import FILTERDEFAULTS
 from pylot.core.util import fnConstructor
 from pylot.core.util import checkurl
+from pylot.core.util import FormatError
 from pylot.core.util import layoutStationButtons
 from pylot.core.util import (FilterOptionsDialog,
                              MPLWidget,

pylot/core/util/__init__.py

@@ -1,6 +1,7 @@
 from pylot.core.util.connection import checkurl
 from pylot.core.util.defaults import FILTERDEFAULTS
 from pylot.core.util.errors import OptionsError
+from pylot.core.util.errors import FormatError
 from pylot.core.util.layouts import layoutStationButtons
 from pylot.core.util.utils import fnConstructor
 from pylot.core.util.widgets import PickDlg