[gnome-photos] tool-filters: Add a context and translator comment

[Debarshi Ray <debarshir src gnome org>]

commit 678dc00e8bc9bd5e3277f08baa020e6e22cca5ec
Author: Debarshi Ray <debarshir gnome org>
Date:   Sat Mar 5 18:52:17 2016 +0100

    tool-filters: Add a context and translator comment
    
    https://bugzilla.gnome.org/show_bug.cgi?id=763131

 src/photos-tool-filters.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/photos-tool-filters.c b/src/photos-tool-filters.c
index 84059d2..efa51b5 100644
--- a/src/photos-tool-filters.c
+++ b/src/photos-tool-filters.c
@@ -188,7 +188,8 @@ photos_tool_filters_init (PhotosToolFilters *self)
 
   self->grid = g_object_ref_sink (gtk_grid_new ());
 
-  button = photos_tool_filter_button_new (group, _("None"));
+  /* Translators: "None" refers to the nop magic filter when editing. */
+  button = photos_tool_filter_button_new (group, C_("Edit Filter", "None"));
   gtk_actionable_set_action_name (GTK_ACTIONABLE (button), "app.insta-current");
   gtk_actionable_set_action_target (GTK_ACTIONABLE (button), "n", (gint16) 
PHOTOS_OPERATION_INSTA_PRESET_NONE);
   gtk_grid_attach (GTK_GRID (self->grid), button, 0, row, 1, 1);