No new mail tooltip should also list sources

[Ashok Vadekar]

When the mouse hovers over the plugin icon and new mail is present, then tooltip is populated with a total new-message count and a breakdown of all the counts from the sources that contribute to that count. But when the new message-count is zero, it says "No new mail" without indicating what sources have no new mail. This is particularly obvious when there is only one source for each of multiple instances of the plugin. You have to know the order of the icons to remember what account it is that has no new mail.

I suggest that when no new mail is being reported, it should also list the sources that it is claiming have no new mail.