Log Message:
Update gtk3 to 3.6.1

* The accessibility bridge code that exports accessible objects
  on the bus is now used by default; atk-bridge has been converted
  into a library that GTK+ links against. To void the linking,
  pass --without-atk-bridge when configuring GTK+.

* GDK threading support has been deprecated. It is recommended to
  use g_idle_add(), g_main_context_invoke() and similar funtions
  to make all GTK+ calls from the main thread.

* GTK+ now follows the XDG Base Directory specification for
  user configuration and data files. In detail,
  * $XDG_CONFIG_HOME/gtk-3.0/custom-papers is the new location
    for $HOME/.gtk-custom-papers
  * $XDG_CONFIG_HOME/gtk-3.0/bookmarks is the new location
    for $HOME/.gtk-bookmarks
  * $XDG_DATA_HOME/themes is preferred over $HOME/.themes
  * $XDG_DATA_HOME/icons is preferred over $HOME/.icons.
  Existing files from the old location will still be read
  if the new location does not exist.

* $HOME/.gtk-3.0 is no longer in the default module load path.
  If you want to load modules from there, add it to the GTK_PATH
  environment variable.