Locale module variables not uninstalled, causes fatal errors

Steps to reproduce:
1. Enable locale.module
2. Add another language besides the default English
3. Disable and uninstall locale.module

You'll get fatal errors due to the {languages} table not being found because in language_list() which is called from drupal_init_language/language_initialize in bootstrap will fail on this logic:

  // Init language list
  if (!isset($languages)) {
    if (variable_get('language_count', 1) > 1 || module_exists('locale')) {
      $result = db_query('SELECT * FROM {languages} ORDER BY weight ASC, name ASC');
      while ($row = db_fetch_object($result)) {
        $languages['language'][$row->language] = $row;
      }
    }
    else {
      // No locale module, so use the default language only.
      $default = language_default();
      $languages['language'][$default->language] = $default;
    }
  }

Because the language_count variable was never deleted, it still has a value of 2, and so tries to access a table that no longer exists. We need to backport the locale.module uninstall routine from D7.