Fix exported headers in Core and TextEditor.

- Unexport Core::Internal::MainWindow and remove its includes.
- Move RssFetcher from Core::Internal to Core.
- Unexport CopyTaskHandler.
- Move TextEditor's completion support and Refactor Overlay
  helper classes from TextEditor::Internal to TextEditor as they
  are exported.
- Move internal BaseTextBlockSelection into private header.
- Unexport TextEditorOverlay as they are not used.

src/plugins/texteditor/refactoroverlay.h

@@ -1,13 +1,42 @@
+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** Commercial Usage
+**
+** Licensees holding valid Qt Commercial licenses may use this file in
+** accordance with the Qt Commercial License Agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Nokia.
+**
+** GNU Lesser General Public License Usage
+**
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at http://qt.nokia.com/contact.
+**
+**************************************************************************/
+
 #ifndef REFACTOROVERLAY_H
 #define REFACTOROVERLAY_H
 
-#include "basetexteditor.h"
+#include "texteditor_global.h"
 
 #include <QtGui/QTextCursor>
 #include <QtGui/QIcon>
 
 namespace TextEditor {
-namespace Internal {
+class BaseTextEditor;
 
 struct  TEXTEDITOR_EXPORT RefactorMarker {
     inline bool isValid() const { return !cursor.isNull(); }
@@ -41,11 +70,9 @@ private:
     RefactorMarkers m_markers;
     BaseTextEditor *m_editor;
     int m_maxWidth;
-    QIcon m_icon;
-
+    const QIcon m_icon;
 };
 
-}
-}
+} // namespace TextEditor
 
 #endif // REFACTOROVERLAY_H