update_status 5.x-2.0-rc2

Changes since 5.x-2.0-rc:

• #155483: Backported numerous improvements from update.module in D6 core:
  • General:
    • The module now nags site administrators on admin/* if the site is missing a security update.
    • Added a drupal_set_message() when fetching data manually (success or failure) and cleaned up wording of watchdog().
    • Added watchdog() error message when you can't fetch any data.
    • The menu callback for manually checking is now at 'admin/logs/updates/check'.
    • Lots of internal improvements to the code to improve clarity.
  • Available updates report:
    • Used format_interval() for the "Last checked:" date and time.
    • Removed the "Ignored" part whenever a row on the update report is yellow, except for when something is ignored because of the settings.
    • Changed the wording when the "Notification threshold" is set to "Only security updates", and you have a non-security update available. Now, it just says "Update available".
    • Added support for a variable to override the default fetch URL.
  • Settings page:
    • Moved the email notification setting to the top of the page.
    • Renamed "Error threshold" to "Notification threshold" and improved the description.
    • Fixed t() bug in form_set_error() during email validation.
    • Removed the setting to opt out of the usage reporting. No one who's willing to run this module in the first place could possibly complain about the random string appended as a query arg on the fetch URL, and the extra setting needlessly complicates the settings page.
• Fixed a notice on the status report page when the available update cache is empty: we were generating a 1/2 constructed line for core and a full line for contrib. Now, if the cache is empty, we just generate the warning line for core and nothing for contrib.
• Fixed minor bug: the status report text was missing a space.
• Fixed bug caused by variable name typo: $base_util vs. $base_url.
• Made the status report table all 100% wide for a more consistent UI.
• #155281: Use flexible path for serving/fetching release history.
• #155428: Removed the human-readable menu path from the notification email since it was considered a burden to translate.
• Added an implementation of hook_uninstall() to purge variables. It's important that when sites running this want to upgrade to D6 that they first uninstall this module, or they'll be left with stale variables.
• Updated README.txt to reflect recent changes and to mention uninstalling the module before upgrading to 6.x core.