Force emoji presentation

Append a variation selector to the Emoji sequences,
to force Emoji presentation. Without this, some
Emoji come out with text presentation by default.

Closes: Pango #334

gtk/gtkemojichooser.c

@@ -392,6 +392,7 @@ add_emoji (GtkWidget    *box,
         p += g_unichar_to_utf8 (code, p);
     }
   g_variant_unref (codes);
+  p += g_unichar_to_utf8 (0xFE0E, p); /* U+FE0F is the Emoji variation selector */
   p[0] = 0;
 
   label = gtk_label_new (text);

gtk/gtkemojicompletion.c

@@ -474,6 +474,7 @@ get_text (GVariant *emoji_data,
         p += g_unichar_to_utf8 (code, p);
     }
   g_variant_unref (codes);
+  p += g_unichar_to_utf8 (0xFE0F, p); /* U+FE0F is the Emoji variation selector */
   p[0] = 0;
 }