Implement renaming of tools and categories.

Not possible to reset them yet.
Saves the change in the settings instead of writing new tools xml files.
This probably needs to be adapted for tools that are "local" from the
beginning.

src/plugins/coreplugin/mainwindow.h

@@ -53,6 +53,7 @@ namespace Core {
 class ActionManager;
 class StatusBarWidget;
 class EditorManager;
+class ExternalToolManager;
 class FileManager;
 class HelpManager;
 class IWizard;
@@ -189,6 +190,7 @@ private:
     mutable QPrinter *m_printer;
     ActionManagerPrivate *m_actionManager;
     EditorManager *m_editorManager;
+    ExternalToolManager *m_externalToolManager;
     FileManager *m_fileManager;
     MessageManager *m_messageManager;
     ProgressManagerPrivate *m_progressManager;