glib: Use C struct for PopplerPageRange

Boxed type is not needed so use just common C struct.
Use G_GNUC_MALLOC attribute on
poppler_document_get_print_page_ranges().

https://gitlab.freedesktop.org/poppler/poppler/issues/290
diff --git a/glib/poppler-document.cc b/glib/poppler-document.cc
index acd8157..c0c3fc0 100644
--- a/glib/poppler-document.cc
+++ b/glib/poppler-document.cc
@@ -1662,7 +1662,7 @@
  *
  * Returns: a #PopplerPrintDuplex that should be used when document is printed
  *
- * Since: 0.78
+ * Since: 0.80
  **/
 PopplerPrintDuplex
 poppler_document_get_print_duplex (PopplerDocument *document)
@@ -1706,7 +1706,7 @@
  *
  * Returns: Number of copies
  *
- * Since: 0.78
+ * Since: 0.80
  **/
 gint
 poppler_document_get_print_n_copies (PopplerDocument *document)
@@ -1728,53 +1728,6 @@
   return retval;
 }
 
-/* PopplerPageRange */
-
-POPPLER_DEFINE_BOXED_TYPE (PopplerPageRange, poppler_page_range,
-			   poppler_page_range_copy,
-			   poppler_page_range_free)
-
-/**
- * poppler_page_range_new:
- *
- * Creates a new #PopplerPageRange
- *
- * Returns: a new #PopplerPageRange, use poppler_page_range_free() to free it
- */
-PopplerPageRange *
-poppler_page_range_new (void)
-{
-  return g_slice_new0 (PopplerPageRange);
-}
-
-/**
- * poppler_page_range_copy:
- * @range: a #PopplerPageRange to copy
- *
- * Creates a copy of @range
- *
- * Returns: a new allocated copy of @range
- */
-PopplerPageRange *
-poppler_page_range_copy (PopplerPageRange *range)
-{
-  g_return_val_if_fail (range != nullptr, NULL);
-
-  return g_slice_dup (PopplerPageRange, range);
-}
-
-/**
- * poppler_page_range_free:
- * @range: a #PopplerPageRange
- *
- * Frees the given #PopplerPageRange
- */
-void
-poppler_page_range_free (PopplerPageRange *range)
-{
-  g_slice_free (PopplerPageRange, range);
-}
-
 /**
  * poppler_document_get_print_page_ranges:
  * @document: A #PopplerDocument
@@ -1787,7 +1740,7 @@
  *          of #PopplerPageRanges or NULL. Free the array when
  *          it is no longer needed.
  *
- * Since: 0.78
+ * Since: 0.80
  **/
 PopplerPageRange *
 poppler_document_get_print_page_ranges (PopplerDocument *document,
@@ -2342,7 +2295,7 @@
   /**
    * PopplerDocument:print-duplex:
    *
-   * Since: 0.78
+   * Since: 0.80
    */
   g_object_class_install_property (G_OBJECT_CLASS (klass),
 				   PROP_PRINT_DUPLEX,
@@ -2358,7 +2311,7 @@
    *
    * Suggested number of copies to be printed for this document
    *
-   * Since: 0.78
+   * Since: 0.80
    */
   g_object_class_install_property (G_OBJECT_CLASS (klass),
 				   PROP_PRINT_N_COPIES,
diff --git a/glib/poppler-document.h b/glib/poppler-document.h
index 499991c..9d8b705 100644
--- a/glib/poppler-document.h
+++ b/glib/poppler-document.h
@@ -161,7 +161,7 @@
  *
  * Duplex viewer preference
  *
- * Since: 0.78
+ * Since: 0.80
  */
 typedef enum
 {
@@ -400,7 +400,7 @@
 gint               poppler_document_get_print_n_copies     (PopplerDocument *document);
 POPPLER_PUBLIC
 PopplerPageRange  *poppler_document_get_print_page_ranges  (PopplerDocument *document,
-                                                            int             *n_ranges);
+                                                            int             *n_ranges) G_GNUC_MALLOC;
 
 /* Attachments */
 POPPLER_PUBLIC
@@ -531,25 +531,14 @@
  *
  * A #PopplerPageRange is used to specify a range of pages.
  *
- * Since: 0.78
+ * Since: 0.80
  */
-#define POPPLER_TYPE_PAGE_RANGE               (poppler_page_range_get_type ())
 struct _PopplerPageRange
 {
   gint start_page;
   gint end_page;
 };
 
-POPPLER_PUBLIC
-GType             poppler_page_range_get_type (void) G_GNUC_CONST;
-POPPLER_PUBLIC
-PopplerPageRange *poppler_page_range_new      ();
-POPPLER_PUBLIC
-PopplerPageRange *poppler_page_range_copy     (PopplerPageRange *range);
-POPPLER_PUBLIC
-void              poppler_page_range_free     (PopplerPageRange *range);
-
-
 G_END_DECLS
 
 #endif /* __POPPLER_DOCUMENT_H__ */