When a QtChatWindow's text input receives focus, it initiates a one second timer. When it times out, the QtChatWindow checks whether the QtChatWindow in general has focus. If so, it will reset the unread count to 0. If it doesn't still have focus, it will not alter the message count and the chat will still show as having unread messages. Test-Information: This is in the Qt user interface, so no unit tests have been written. Tested thoroughly on a test server on ubuntu 17.10. Tested what happens when the chat window is changed via both a click on the roster (both old and new) and a click on the tabs. All three scenarios produce the desired results when both keeping focus for the full second, or when losing focus before the second is up. Change-Id: Idfa66990545051cfe6c9853418b2138ee0f1f57c