TextEditor: Factory cosmetics

Pimpl, add some convenience setters.

Change-Id: I525c080179fddab6fe2bd2270505fdbf33e56be2
Reviewed-by: David Schulz <david.schulz@digia.com>

src/plugins/cppeditor/cppeditorplugin.cpp

@@ -91,6 +91,9 @@ public:
         setEditorCreator([]() { return new CppEditor; });
         setAutoCompleterCreator([]() { return new CppAutoCompleter; });
         setCommentStyle(Utils::CommentDefinition::CppStyle);
+        setCodeFoldingSupported(true);
+        setMarksVisible(true);
+        setParenthesesMatchingEnabled(true);
 
         setEditorActionHandlers(TextEditorActionHandler::Format
                               | TextEditorActionHandler::UnCommentSelection