Language setting not taken into account when adding new menu items

A note to the clueless:
This bug only applies if you have the "Menu Translation" module (i18nmenu) enabled.
(submodule shipped with i18n)

The fix is quite simple:
I just need to set the default value for language to an empty string.

However, there is some other stuff I need to take into account for the i18nmenu.
Basically, I have to copy the mechanics from the menu_edit_item form.
This form is modified by i18nmenu_form_menu_edit_item_alter(), and gets additional validation and submit callbacks:

<?php
  array_unshift($form['#validate'], 'i18nmenu_menu_item_prepare_normal_path');
  $form['#submit'][] = 'i18nmenu_menu_item_update';
?>

The i18nmenu_menu_item_update() calls _i18nmenu_update_item(), which calls _i18nmenu_get_item(), which calls tt(), which calls i18nstrings_update_string(), which calls i18nstrings_add_string(), which writes to db tables {locales_source}, {locales_target}, {i18n_strings}. Just so you get an idea..

For the submit mechanics it will probably be enough to call _i18nmenu_update_item() for every new or modified item, after it has been saved.

For validation, I should first add some very basic checks, then I can add i18nmenu_menu_item_prepare_normal_path().

A new version is on CVS, including:
- the bug fix for language settings
- the bug fix for order of items
- a bunch of new features
- probably some new bugs.

I hope the packaging script will run soon.

Packaging script has run, and the fixed code can be downloaded with the latest 6.x-1.x snapshot.

There is no status "committed to snapshot release", so I set this to "needs review".
Others would set it to "fixed", but I don't like this. It's fixed when it's officially released!