Unread notifier for TB

This software couples together with the extension TB Menubar Unread Notifier. It reads the output produced by the extension and show the corresponding status of the number of messages received by Thunderbird. If there is no message, an empty box is shown on the menubar. If there is one unread message, the box is fill with a white envolop. If there are more than two, a number is displayed next to the box. If there are more than 99 unread messages, a start is displayed rather than a number.