[gimp] Update NEWS

[Alexandre Prokoudine <aprokoudine src gnome org>]

commit cb61c087e249a77e3e9675e3d70c4b2309b8ba68
Author: Alexandre Prokoudine <alexandre prokoudine gmail com>
Date:   Sun Jun 4 08:16:16 2017 +0300

    Update NEWS

 NEWS |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index 267181c..b775cf0 100644
--- a/NEWS
+++ b/NEWS
@@ -195,6 +195,9 @@ Plug-ins
   - For GEGL-based tools, use a new metadata language to dynamically
     control UI attributes based on context (e.g. auto-disable
     unapplicable options).
+  - Allow filter actions to have hardcoded default operation settings
+    by encoding them directly in the string attached to all filter
+    actions.
 
 Color Palettes