[gnome-tweak-tool] Support versioned Gtk3 themes

[Patrick Griffis <pgriffis src gnome org>]

commit f47ba28fbb2c895a88d4e5ca8b89bc18475a86e9
Author: Patrick Griffis <tingping tingping se>
Date:   Wed Mar 23 20:39:20 2016 -0400

    Support versioned Gtk3 themes

 gtweak/tweaks/tweak_group_interface.py |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/gtweak/tweaks/tweak_group_interface.py b/gtweak/tweaks/tweak_group_interface.py
index ed2ad5f..97751ed 100644
--- a/gtweak/tweaks/tweak_group_interface.py
+++ b/gtweak/tweaks/tweak_group_interface.py
@@ -46,12 +46,17 @@ class GtkThemeSwitcher(GSettingsComboTweak):
 
     def _get_valid_themes(self):
         """ Only shows themes that have variations for gtk+-3 and gtk+-2 """
+        gtk_ver = Gtk.MINOR_VERSION
+        if gtk_ver % 2: # Want even number
+            gtk_ver += 1
+
         dirs = ( os.path.join(gtweak.DATA_DIR, "themes"),
                  os.path.join(GLib.get_user_data_dir(), "themes"),
                  os.path.join(os.path.expanduser("~"), ".themes"))
         valid = walk_directories(dirs, lambda d:
                     os.path.exists(os.path.join(d, "gtk-2.0")) and \
-                        os.path.exists(os.path.join(d, "gtk-3.0")))
+                        (os.path.exists(os.path.join(d, "gtk-3.0")) or \
+                         os.path.exists(os.path.join(d, "gtk-3.{}".format(gtk_ver)))))
         return valid
 
 class IconThemeSwitcher(GSettingsComboTweak):