refactoring: take ignore_list out of Scanner class

It's now `DupeGuru` that holds it and passes it to `get_dupe_groups()`,
the only place where it's actually used in `Scanner`.

This will make the SE/ME/PE merge easier by allowing us to instantiate
the Scanner on-the-fly since it doesn't hold state anymore.

core/gui/ignore_list_dialog.py

@@ -1,8 +1,8 @@
 # Created On: 2012/03/13
 # Copyright 2015 Hardcoded Software (http://www.hardcoded.net)
-# 
-# This software is licensed under the "GPLv3" License as described in the "LICENSE" file, 
-# which should be included with this package. The terms are also available at 
+#
+# This software is licensed under the "GPLv3" License as described in the "LICENSE" file,
+# which should be included with this package. The terms are also available at
 # http://www.gnu.org/licenses/gpl-3.0.html
 
 from hscommon.trans import tr
@@ -12,12 +12,12 @@ class IgnoreListDialog:
     #--- View interface
     # show()
     #
-    
+
     def __init__(self, app):
         self.app = app
-        self.ignore_list = self.app.scanner.ignore_list
+        self.ignore_list = self.app.ignore_list
         self.ignore_list_table = IgnoreListTable(self)
-    
+
     def clear(self):
         if not self.ignore_list:
             return
@@ -25,15 +25,15 @@ class IgnoreListDialog:
         if self.app.view.ask_yes_no(msg):
             self.ignore_list.Clear()
             self.refresh()
-    
+
     def refresh(self):
         self.ignore_list_table.refresh()
-    
+
     def remove_selected(self):
         for row in self.ignore_list_table.selected_rows:
             self.ignore_list.remove(row.path1_original, row.path2_original)
         self.refresh()
-    
+
     def show(self):
         self.view.show()
-    
+