dhtml_menu 6.x-3.5

This is primarily a bugfix release, though several translations were added.

Bugs
- Far too many issues to name: The latest hook_update_N had a NULL instead of an array() return value, causing countless people to see a completely meaningless type warning.
- #297536 while traversing the menu tree, an is_array check ensures that no type warnings are emitted.
- #356495: The tree-indexing now stores ancestor trails for each menu item, removing reliance on the stack from recursive calls to theme_menu_item_link and theme_menu_item. This reliance was breaking the module whenever the theme functions were called elsewhere, eg. by NiceMenu.

Translations
- Swedish translation updated
- Ukrainian translation added
- Dutch translation added
- #454700: Polish translation added