[gtkmm] Correct NEWS

[Murray Cumming <murrayc src gnome org>]

commit 22924c05461071aa0ea6112c5dbb7d1ad1f6b313
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Feb 28 10:53:50 2012 +0100

    Correct NEWS

 NEWS |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index a51f007..3c26fb7 100644
--- a/NEWS
+++ b/NEWS
@@ -20,6 +20,9 @@ Gtk:
   (Murray Cumming)
 * EntryBuffer: Correct the EntryBuffer(name) constructor.
   Bug #670784 (Marcus Yass)
+* Grid: Add get_child_at(), insert_row(),
+  insert_row(), insert_column(), insert_next_to().
+  (Mark Vender) Bug #670238
 * TextTag: Add RGBA versions of the properties.
   (Murray Cumming)
 * Window: set_background(Color): Deprcate this.