Comment 2 for bug 329296

An updated patch. This fixes a memory leak in the previous patch (the hash table entry wasn't freed after the alert callback is executed). This also addresses the following issues that I failed to post in the bug description above:

Another situation is fairly common, but any response involves the hardware rather than the software, so it should use a notification bubble:

    * “Battery Discharging”, “The AC power has been unplugged. The system is now using battery power.” with a “Do not show me this again” button. This button should be made conditional on whether the notification server supports actions.

Two others should put up neither a notification bubble nor an alert, so their bubbles should be removed:

    * “Sleep warning”, “Your laptop will not sleep if you shut the lid as a running program has prevented this. Some laptops can overheat if they do not sleep when the lid is closed.”
    * “Battery Charged”, “Your laptop battery is now fully charged”.