[gnome-software] Sync news from 3.28 branch

[Kalev Lember <klember src gnome org>]

commit 43cfd4209e35676bbc99a274a8153aafb0298bc2
Author: Kalev Lember <klember redhat com>
Date:   Wed May 9 11:01:50 2018 +0200

    Sync news from 3.28 branch

 NEWS                                           | 13 +++++++++++++
 data/appdata/org.gnome.Software.appdata.xml.in | 15 +++++++++++++++
 2 files changed, 28 insertions(+)
---
diff --git a/NEWS b/NEWS
index 63705331..2655f9e9 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,16 @@
+Version 3.28.2
+~~~~~~~~~~~~~~
+Released: 2018-05-09
+
+This is a stable release with the following changes:
+ * Add a warning when enabling the LVFS remote
+ * Show a notification when failing to open an url or a local file
+ * Fix multiple flatpak refreshes with new libflatpak
+ * Build fixes for FreeBSD
+ * Icon loading fixes for snap
+
+This release also updates translations.
+
 Version 3.28.1
 ~~~~~~~~~~~~~~
 Released: 2018-04-09
diff --git a/data/appdata/org.gnome.Software.appdata.xml.in b/data/appdata/org.gnome.Software.appdata.xml.in
index 6237d34f..d6ae441a 100644
--- a/data/appdata/org.gnome.Software.appdata.xml.in
+++ b/data/appdata/org.gnome.Software.appdata.xml.in
@@ -46,6 +46,21 @@
    Validate with `appstream-util validate *.appdata.xml`
   -->
   <releases>
+    <release date="2018-05-09" version="3.28.2">
+      <description>
+        <p>
+          This is a stable release with the following changes:
+        </p>
+        <ul>
+          <li>Add a warning when enabling the LVFS remote</li>
+          <li>Show a notification when failing to open an url or a local file</li>
+          <li>Fix multiple flatpak refreshes with new libflatpak</li>
+          <li>Build fixes for FreeBSD</li>
+          <li>Icon loading fixes for snap</li>
+        </ul>
+        <p>This release also updates translations.</p>
+      </description>
+    </release>
     <release date="2018-04-09" version="3.28.1">
       <description>
         <p>