[dconf/version/0.40.0] build: update NEWS and version for 0.40.0

[Daniel Playfair Cal <danielplayfaircal src gnome org>]

commit 888ad6eeb0a961ab3503022a75e46215af88c041
Author: Daniel Playfair Cal <daniel playfair cal gmail com>
Date:   Sat Mar 13 11:53:14 2021 +1100

    build: update NEWS and version for 0.40.0

 NEWS        | 7 +++++++
 meson.build | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)
---
diff --git a/NEWS b/NEWS
index bb70bef..23a2eae 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,10 @@
+Changes in dconf 0.40.0
+=======================
+
+ - common: Add missing G_BEGIN/END_DECLS to allow use of headers from C++
+   code (Philip Withnall, !67)
+
+
 Changes in dconf 0.39.1
 =======================
 
diff --git a/meson.build b/meson.build
index 28a3e5b..1de865c 100644
--- a/meson.build
+++ b/meson.build
@@ -1,6 +1,6 @@
 project(
   'dconf', ['c'],
-  version: '0.39.2',
+  version: '0.40.0',
   license: 'LGPL2.1+',
   meson_version: '>= 0.47.0',
 )