[babl] NEWS: update news for 0.1.58 release

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 6c79b3dc12a1a4f853ad3dd32428df7e798b89fd
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Sep 19 12:01:55 2018 +0200

    NEWS: update news for 0.1.58 release

 NEWS | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/NEWS b/NEWS
index a7d93e1..dc0f00c 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,13 @@ The NEWS file in the babl source tree is the source location for
 the news section both in the README and the webpage.
                                                                           -->
 
+2018-09-19 babl-0.1.58                                              </dt><dd>
+Preserve color of transparent pixels in conversion to premultiplied alpha,
+Added single precision code-paths for faster fallback/reference conversions.
+New BABL_ICC_INTENT_PERFORMANCE bitflag for or-ing into intent, permitting
+use of matrix+trc when relative colorimetric CLUT is present.
+
+                                                                    </dd><dt>
 2018-08-14 babl-0.1.56                                              </dt><dd>
 Improvements to the caching of profiled conversion chains between invocations
 by ignoring unknown bits in cache file and remember which conversions yielded