[gnome-flashback] bump version to 3.40.0, update NEWS

[Alberts Muktupāvels <muktupavels src gnome org>]

commit e68b9f3578af7cdd0eeacbcb412d278d51c760bf
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Thu Mar 25 16:24:14 2021 +0200

    bump version to 3.40.0, update NEWS

 NEWS         | 5 +++++
 configure.ac | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/NEWS b/NEWS
index 613712c..edd53a7 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,8 @@
+Version 3.40.0
+==============
+- Fix background drawing when using spanned or wallpaper option. (#66)
+- Updated translations.
+
 Version 3.38.0
 ==============
 - Configure systemd session using a drop-in.
diff --git a/configure.ac b/configure.ac
index a022721..0e1f6ce 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,7 +3,7 @@ dnl Define version info
 dnl **************************************************************************
 
 m4_define([gf_major_version], [3])
-m4_define([gf_minor_version], [38])
+m4_define([gf_minor_version], [40])
 m4_define([gf_micro_version], [0])
 m4_define([gf_version], [gf_major_version.gf_minor_version.gf_micro_version])