TextEditors: Move some auto-indentation code to document

From the editor widget. Also name them autoIndent/autoReindent to
distinguish from the manual indent functions.

Change-Id: I4e1b9d503f53870b669fee66467e5e567eacefec
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/texteditor/basetextdocument.h

@@ -75,6 +75,8 @@ public:
 
     void setIndenter(Indenter *indenter);
     Indenter *indenter() const;
+    void autoIndent(const QTextCursor &cursor, QChar typedChar = QChar::Null);
+    void autoReindent(const QTextCursor &cursor);
 
     ITextMarkable *markableInterface() const;