This gives the actual webcontent more space to work with,
it also emulates how other browsers does it.
In the future we'd like to do something else since only ToolTip
can be visible at the same time.
This patch removes the browser WebView from the window and places it
inside a Tab object, all wrapped up in a QT tab control. So far you can
create tabs, but can't close them.
This patch adds an event handler to the main window which allows it to
respond to a user closing the window. This event is then passed on to
the LibCore event loop, which allows the application quit itself.
Previously the application would hang, only running in the background,
until killed by an external force.
