EditorManager: Close documents instead of editors where appropriate

This is the first step in actually making "closeEditor(s)" close editors
instead of documents.

Change-Id: I02761e0cef950b8fc093f65a90df04a9a7550681
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/debugger/memoryagent.cpp

@@ -104,11 +104,11 @@ void MemoryAgent::closeEditors()
     if (m_editors.isEmpty())
         return;
 
-    QList<IEditor *> editors;
+    QSet<IDocument *> documents;
     foreach (QPointer<IEditor> editor, m_editors)
         if (editor)
-            editors.append(editor.data());
-    EditorManager::closeEditors(editors);
+            documents.insert(editor->document());
+    EditorManager::closeDocuments(documents.toList());
     m_editors.clear();
 }