[librsvg] Update NEWS

[Federico Mena Quintero <federico src gnome org>]

commit a11f5d68e555c5231d0adcbaf83d963e53c65764
Author: Federico Mena Quintero <federico gnome org>
Date:   Mon Oct 28 17:14:32 2019 -0600

    Update NEWS

 NEWS | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
---
diff --git a/NEWS b/NEWS
index 59fd17f9..4b23db8a 100644
--- a/NEWS
+++ b/NEWS
@@ -16,6 +16,21 @@ Version 2.47.0
           xmlns:xi="http://www.w3.org/2001/XInclude";>
            ^^^^^^^^^ these ones
 
+- Patterns and gradients reused across more than one element will only
+  get resolved once now; this should make things marginally faster for
+  patterns or gradients with fallbacks.
+
+- #515 - Librsvg now has limits on the number of loaded XML elements,
+  and the number of referenced elements within an SVG document.  This
+  is to mitigate malicious SVGs which try to consume all memory, and
+  those which try to consume an exponential amount of CPU time.
+
+- #521 - Compute geometries correctly if there is a viewBox attribute.
+
+- #308 - Fix stack exhaustion with circular references in <use> elements.
+
+- Consistently use the LGPL 2.1 wherever it is mentioned.
+
 - Patterns and gradients reused across more than one element will only
   get resolved once now; this should make things marginally faster for
   patterns or gradients with fallbacks.