Update NEWS for the 2.1.7 release

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

NEWS

 News
 ====
 
+Version 2.1.7
+-------------
+
+*(Released Tue, 24 Aug 2010)*
+
+Bugfixes only:
+  - Don't ignore secondary node silently on non-mirrored disk templates
+    (issue 113)
+  - Fix --master-netdev arg name in gnt-cluster(8) (issue 114)
+  - Fix usb_mouse parameter breaking with vnc_console (issue 109)
+  - Properly document the usb_mouse parameter
+  - Fix path in ganeti-rapi(8) (issue 116)
+  - Adjust error message when the ganeti user's .ssh directory is
+    missing
+  - Add same-node-check when changing the disk template to drbd
+
 Version 2.1.6
 -------------