C++ symbols find filter for advanced find.

Required refactoring of the search result window to show real trees of
search results.

The backend is the backend from the Locator filter, which is a bit
outdated now.

src/plugins/texteditor/findincurrentfile.cpp

@@ -62,11 +62,6 @@ QString FindInCurrentFile::displayName() const
     return tr("Current File");
 }
 
-QKeySequence FindInCurrentFile::defaultShortcut() const
-{
-    return QKeySequence();
-}
-
 Utils::FileIterator *FindInCurrentFile::files()
 {
     QStringList fileList;