[gcalctool] Update NEWS

[Robert Ancell <rancell src gnome org>]

commit f82a822af92bf743d5ec3b858c6aa04c4d8e404b
Author: Robert Ancell <robert ancell canonical com>
Date:   Wed Jan 5 15:33:12 2011 +1100

    Update NEWS

 NEWS |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index 7148b30..525bfca 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,9 @@
+Overview of changes in gcalctool 5.91.5
+
+    * Make new variable buttons that combines add/set/get and clear into one
+      dialog.
+    * Add a decimal point button to the programming mode
+
 Overview of changes in gcalctool 5.91.4
 
     * Use new Indian Rupee sign â?¹ (Bug #636587, Carlos Cejudo)