[gtk-doc] release: update news and date in manual

[Stefan Sauer <stefkost src gnome org>]

commit 695816a36b492140529ed84c59ee246be2b952b7
Author: Stefan Sauer <ensonic users sf net>
Date:   Sat Mar 24 16:10:34 2018 +0100

    release: update news and date in manual

 NEWS                        |   27 +++++++++++++++++++++++++--
 configure.ac                |    2 +-
 help/manual/C/index.docbook |    6 +++---
 3 files changed, 29 insertions(+), 6 deletions(-)
---
diff --git a/NEWS b/NEWS
index 71f198f..d8fc4f9 100644
--- a/NEWS
+++ b/NEWS
@@ -1,7 +1,30 @@
-GTK-Doc 1.27.1  (Dec 07 2017)
+GTK-Doc 1.28  (Mar 24 2018)
 ==============
 
-Development.
+Bug fixes.
+
+ Changes
+
+ o 791928 : gtk-doc doesn't understand 'stability: Obsolete'
+ o 792148 : cmake: Installed GtkDocConfig.cmake has incorrect bindir path
+ o 792661 : use pygments to do syntax highlighing
+ o 793599 : Please run testsuite with V=0
+ o 794051 : rebase: fix on-line location extraction from devhelp files
+ o 794182 : private_header regex is broken
+
+ Contributors
+
+ Anders Jonsson
+ Arnaud Rebillout
+ Behdad Esfahbod
+ Bruce Mitchener
+ Daniel Mustieles
+ Marek Černocký
+ Rafael Fontenelle
+ Stefan Sauer
+ Tim-Philipp Müller
+ Tim Sabsch
+
 
 GTK-Doc 1.27  (Dec 07 2017)
 ==============
diff --git a/configure.ac b/configure.ac
index 319dfb1..05500b9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,7 +3,7 @@ AC_PREREQ([2.63])
 
 dnl We're using a two digit number for the releases and
 dnl a three digit number for the development version
-m4_define(gtk_doc_version, 1.27.1)
+m4_define(gtk_doc_version, 1.28)
 
 AC_INIT([gtk-doc],[gtk_doc_version],[http://bugzilla.gnome.org/enter_bug.cgi?product=gtk-doc],[gtk-doc])
 
diff --git a/help/manual/C/index.docbook b/help/manual/C/index.docbook
index c89d9f9..0980f3f 100644
--- a/help/manual/C/index.docbook
+++ b/help/manual/C/index.docbook
@@ -81,10 +81,10 @@
 
     <revhistory>
       <revision>
-         <revnumber>1.27.1</revnumber>
-         <date>07 Dec 2017</date>
+         <revnumber>1.28</revnumber>
+         <date>24 Mar 2018</date>
          <authorinitials>ss</authorinitials>
-         <revremark>development</revremark>
+         <revremark>bug fixes</revremark>
       </revision>
       <revision>
          <revnumber>1.27</revnumber>