[gtksourceview] gtksourcetag.[c|h]: Ensure symbols are annotated for export by macros

[Chun-wei Fan <fanchunwei src gnome org>]

commit d5b1b9ed0ef56388775cfcea03b7161c6a0170f3
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Wed Dec 23 16:13:27 2015 +0800

    gtksourcetag.[c|h]: Ensure symbols are annotated for export by macros
    
    The gtk_source_tag_get_type() symbol is not marked for export via macros as the
    G_DECLARE_DERIVABLE_TYPE that is used to declare it is not annotated.  Also,
    gtksourcetag.c needs to include config.h first if exporting using the compiler-
    specific directives is desired.

 gtksourceview/gtksourcetag.c |    4 ++++
 gtksourceview/gtksourcetag.h |    2 ++
 2 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/gtksourceview/gtksourcetag.c b/gtksourceview/gtksourcetag.c
index 17080c9..b3329f8 100644
--- a/gtksourceview/gtksourcetag.c
+++ b/gtksourceview/gtksourcetag.c
@@ -21,6 +21,10 @@
  * Author: Sébastien Wilmet
  */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include "gtksourcetag.h"
 
 /**
diff --git a/gtksourceview/gtksourcetag.h b/gtksourceview/gtksourcetag.h
index c53c246..a40c067 100644
--- a/gtksourceview/gtksourcetag.h
+++ b/gtksourceview/gtksourcetag.h
@@ -30,6 +30,8 @@
 G_BEGIN_DECLS
 
 #define GTK_SOURCE_TYPE_TAG (gtk_source_tag_get_type ())
+
+GTK_SOURCE_AVAILABLE_IN_3_20
 G_DECLARE_DERIVABLE_TYPE (GtkSourceTag, gtk_source_tag,
                          GTK_SOURCE, TAG,
                          GtkTextTag)