[gimp] app: add a tooltip to the color temperature preset menu button

[Michael Natterer <mitch src gnome org>]

commit 9af78831ea13c4c9ff53b3c547ff26e623d22730
Author: Michael Natterer <mitch gimp org>
Date:   Tue Jul 18 00:28:56 2017 +0200

    app: add a tooltip to the color temperature preset menu button

 app/propgui/gimppropgui-utils.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/app/propgui/gimppropgui-utils.c b/app/propgui/gimppropgui-utils.c
index 1beadac..c6b9d6a 100644
--- a/app/propgui/gimppropgui-utils.c
+++ b/app/propgui/gimppropgui-utils.c
@@ -97,6 +97,10 @@ gimp_prop_kelvin_presets_new (GObject     *config,
   menu = gtk_menu_new ();
   gtk_menu_attach_to_widget (GTK_MENU (menu), button, NULL);
 
+  gimp_help_set_help_data (button,
+                           _("Choose from a list of common "
+                             "color temperatures"), NULL);
+
   g_signal_connect (button, "button-press-event",
                     G_CALLBACK (gimp_prop_kelvin_presets_button_press),
                     menu);