[gimp] Issue #1712: Add translator comment for string "Export Exif...

[Jehan <jehanp src gnome org>]

commit 50bcc8db3c17ba82c202080ca3d8d228afb909c5
Author: Jehan <jehan girinstud io>
Date:   Sun Jun 24 21:09:59 2018 +0200

    Issue #1712: Add translator comment for string "Export Exif...
    
    ... metadata by default".
    Also for other metadata, and doing it both for the tooltip and the label
    of the option.

 app/config/gimprc-blurbs.h       | 9 +++++++++
 app/dialogs/preferences-dialog.c | 9 +++++++++
 2 files changed, 18 insertions(+)
---
diff --git a/app/config/gimprc-blurbs.h b/app/config/gimprc-blurbs.h
index 223473c853..6002f264f9 100644
--- a/app/config/gimprc-blurbs.h
+++ b/app/config/gimprc-blurbs.h
@@ -207,12 +207,21 @@ _("Which plug-in to use for importing raw digital camera files.")
 #define EXPORT_COLOR_PROFILE_BLURB \
 _("Export the image's color profile by default.")
 
+/* Translators: tooltip for configuration option (checkbox).
+ * It determines how file export plug-ins handle Exif by default.
+ */
 #define EXPORT_METADATA_EXIF_BLURB \
 _("Export Exif metadata by default.")
 
+/* Translators: tooltip for configuration option (checkbox).
+ * It determines how file export plug-ins handle XMP by default.
+ */
 #define EXPORT_METADATA_XMP_BLURB \
 _("Export XMP metadata by default.")
 
+/* Translators: tooltip for configuration option (checkbox).
+ * It determines how file export plug-ins handle IPTC by default.
+ */
 #define EXPORT_METADATA_IPTC_BLURB \
 _("Export IPTC metadata by default.")
 
diff --git a/app/dialogs/preferences-dialog.c b/app/dialogs/preferences-dialog.c
index 8f2a50afc8..e6e353dda3 100644
--- a/app/dialogs/preferences-dialog.c
+++ b/app/dialogs/preferences-dialog.c
@@ -1480,12 +1480,21 @@ prefs_dialog_new (Gimp       *gimp,
                                    _("Export the image's color profile by default"),
                                    GTK_BOX (vbox2));
   button = prefs_check_button_add (object, "export-metadata-exif",
+                                   /* Translators: label for configuration option (checkbox).
+                                    * It determines how file export plug-ins handle Exif by default.
+                                    */
                                    _("Export Exif metadata by default when available"),
                                    GTK_BOX (vbox2));
   button = prefs_check_button_add (object, "export-metadata-xmp",
+                                   /* Translators: label for configuration option (checkbox).
+                                    * It determines how file export plug-ins handle XMP by default.
+                                    */
                                    _("Export XMP metadata by default when available"),
                                    GTK_BOX (vbox2));
   button = prefs_check_button_add (object, "export-metadata-iptc",
+                                   /* Translators: label for configuration option (checkbox).
+                                    * It determines how file export plug-ins handle IPTC by default.
+                                    */
                                    _("Export IPTC metadata by default when available"),
                                    GTK_BOX (vbox2));
   hbox = prefs_hint_box_new (GIMP_ICON_DIALOG_WARNING,