This is a followup to 7932e3a as it would otherwise be hard to detect processes
terminated by internally or externally sent signals.
Without this patch the widget continues to operate as if nothing has changed without offering a way to react to the termination from within the application.
QTermWidget only add the TerminalDisplay to qt's owner hierarchy for
automatic cleanup. With each new tab a new Session object will be
created and but never deleted (which would cleanup internally the
history files).
This bugfix simple adds to each Session's parent relationship the
corresponding QTermWidget.
Michael Spencer