[gtk+/gtk-3-22] Popover: Complete depr docs of transitions-enabled

[Daniel Boles <dboles src gnome org>]

commit f29007c177deb21b197c11f6b4bce83f85dc1c81
Author: Daniel Boles <dboles src gnome org>
Date:   Sun Oct 8 23:32:44 2017 +0100

    Popover: Complete depr docs of transitions-enabled
    
    Its getter and setter are deprecated, so copy in the blurb from there.

 gtk/gtkpopover.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkpopover.c b/gtk/gtkpopover.c
index b8818fe..f3b6b7b 100644
--- a/gtk/gtkpopover.c
+++ b/gtk/gtkpopover.c
@@ -1761,6 +1761,10 @@ gtk_popover_class_init (GtkPopoverClass *klass)
    * Whether show/hide transitions are enabled for this popover.
    *
    * Since: 3.16
+   *
+   * Deprecated: 3.22: You can show or hide the popover without transitions
+   *   using gtk_widget_show() and gtk_widget_hide() while gtk_popover_popup()
+   *   and gtk_popover_popdown() will use transitions.
    */
   properties[PROP_TRANSITIONS_ENABLED] =
       g_param_spec_boolean ("transitions-enabled",