Improved documentation for QStyledItemDelegate::eventFilter

Added the notion that enter and return keys are not handled
if editor is of type QTextEdit or QPlainTextEdit.

Change-Id: I9d5cb529bf154c687fab1949fccf37e9da096c85
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>

src/widgets/itemviews/qstyleditemdelegate.cpp

@@ -627,6 +627,9 @@ void QStyledItemDelegate::setItemEditorFactory(QItemEditorFactory *factory)
         \li \uicontrol Esc
     \endlist
 
+    If the \a editor's type is QTextEdit or QPlainTextEdit then \uicontrol Enter and
+    \uicontrol Return keys are \e not handled.
+
     In the case of \uicontrol Tab, \uicontrol Backtab, \uicontrol Enter and \uicontrol Return
     key press events, the \a editor's data is comitted to the model
     and the editor is closed. If the \a event is a \uicontrol Tab key press