gmarkup: Make GMarkupParseContext a boxed type

At the same time, add a refcount and public ref/unref methods.
This makes it usable from introspectable.

https://bugzilla.gnome.org/show_bug.cgi?id=690084

gobject/gboxed.c

@@ -160,6 +160,7 @@ G_DEFINE_BOXED_TYPE (GMainLoop, g_main_loop, g_main_loop_ref, g_main_loop_unref)
 G_DEFINE_BOXED_TYPE (GMainContext, g_main_context, g_main_context_ref, g_main_context_unref)
 G_DEFINE_BOXED_TYPE (GSource, g_source, g_source_ref, g_source_unref)
 G_DEFINE_BOXED_TYPE (GPollFD, g_pollfd, pollfd_copy, g_free)
+G_DEFINE_BOXED_TYPE (GMarkupParseContext, g_markup_parse_context, g_markup_parse_context_ref, g_markup_parse_context_unref)
 
 G_DEFINE_BOXED_TYPE (GThread, g_thread, g_thread_ref, g_thread_unref)
 G_DEFINE_BOXED_TYPE (GChecksum, g_checksum, g_checksum_copy, g_checksum_free)

gobject/glib-types.h

@@ -236,6 +236,15 @@ typedef gsize GType;
  */
 #define G_TYPE_POLLFD (g_pollfd_get_type ())
 
+/**
+ * G_TYPE_MARKUP_PARSE_CONTEXT:
+ *
+ * The #GType for a boxed type holding a #GMarkupParseContext.
+ *
+ * Since: 2.36
+ */
+#define G_TYPE_MARKUP_PARSE_CONTEXT (g_markup_parse_context_get_type ())
+
 /**
  * G_TYPE_KEY_FILE:
  *
@@ -294,6 +303,8 @@ GLIB_AVAILABLE_IN_2_36
 GType   g_thread_get_type          (void) G_GNUC_CONST;
 GLIB_AVAILABLE_IN_2_36
 GType   g_checksum_get_type        (void) G_GNUC_CONST;
+GLIB_AVAILABLE_IN_2_36
+GType   g_markup_parse_context_get_type (void) G_GNUC_CONST;
 
 GLIB_DEPRECATED_FOR('G_TYPE_VARIANT')
 GType   g_variant_get_gtype        (void) G_GNUC_CONST;

gobject/gobject.symbols

@@ -32,6 +32,7 @@ g_variant_type_get_gtype
 g_key_file_get_type
 g_main_loop_get_type
 g_main_context_get_type
+g_markup_parse_context_get_type
 g_source_get_type
 g_pollfd_get_type
 g_closure_get_type