Fix Issue 550: MultiDirChooser cannot handle paths with spaces

Instead of using the general formatter, use formatters.multiFileChooser, which handles paths with spaces.

gooey/gui/components/widgets/choosers.py

@@ -1,3 +1,4 @@
+from gooey.gui import formatters
 from gooey.gui.components.widgets import core
 from gooey.gui.components.widgets.bases import TextContainer, BaseChooser
 
@@ -35,6 +36,9 @@ class MultiDirChooser(BaseChooser):
     # todo: allow wildcard
     widget_class = core.MultiDirChooser
 
+    def formatOutput(self, metadata, value):
+        return formatters.multiFileChooser(metadata, value)
+
 
 class DateChooser(BaseChooser):
     # todo: allow wildcard
@@ -42,4 +46,4 @@ class DateChooser(BaseChooser):
 
 
 class ColourChooser(BaseChooser):
-    widget_class = core.ColourChooser
+    widget_class = core.ColourChooser