[atkmm] Change ABI to atkmm-2.28

[Murray Cumming <murrayc src gnome org>]

commit f73568f3c821b54ababbb89b62ea2c3b69b2159b
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Feb 22 21:46:14 2018 +0100

    Change ABI to atkmm-2.28
    
    Instead of atkmm-2.26. To match the most recent ATK+ version.

 MSVC_Net2017/atkmm-version-paths.props |    2 +-
 atk/atkmm.h                            |    2 +-
 configure.ac                           |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/MSVC_Net2017/atkmm-version-paths.props b/MSVC_Net2017/atkmm-version-paths.props
index aacd207..4c002c3 100644
--- a/MSVC_Net2017/atkmm-version-paths.props
+++ b/MSVC_Net2017/atkmm-version-paths.props
@@ -6,7 +6,7 @@
     <CopyDir>$(GlibEtcInstallRoot)</CopyDir>
     <DefDir>$(SolutionDir)$(Configuration)\$(Platform)\obj\$(ProjectName)\</DefDir>
     <ApiMajorVersion>2</ApiMajorVersion>
-    <ApiMinorVersion>26</ApiMinorVersion>
+    <ApiMinorVersion>28</ApiMinorVersion>
     <ReleaseDllSuffix>-vc$(VSVer)0-$(ApiMajorVersion)_$(ApiMinorVersion)</ReleaseDllSuffix>
     <DebugDllSuffix>-vc$(VSVer)0-d-$(ApiMajorVersion)_$(ApiMinorVersion)</DebugDllSuffix>
     <SigCMajorVersion>3</SigCMajorVersion>
diff --git a/atk/atkmm.h b/atk/atkmm.h
index 6824b4d..ae0b225 100644
--- a/atk/atkmm.h
+++ b/atk/atkmm.h
@@ -39,7 +39,7 @@
  * compilation, but suffices for this simple example. Assuming that your
  * program source file is @c program.cc, compile it with:
  * @code
- * g++ program.cc -o program  `pkg-config --cflags --libs atkmm-2.26`
+ * g++ program.cc -o program  `pkg-config --cflags --libs atkmm-2.28`
  * @endcode
  * Alternatively, if using autoconf, use the following in @c configure.ac:
  * @code
diff --git a/configure.ac b/configure.ac
index 769588a..c3b80cf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,7 +36,7 @@ AM_MAINTAINER_MODE
 AC_ARG_VAR([ACLOCAL_FLAGS], [aclocal flags, e.g. -I <macro dir>])
 
 MM_PREREQ([0.9.10])
-MM_INIT_MODULE([atkmm-2.26])
+MM_INIT_MODULE([atkmm-2.28])
 
 # Copy the mm-common .pl scripts into doc/, and use them from there,
 # so we can dist them to avoid a tarball-build dependency.