GUI variable editor patch pushed and some help needed

[John W. Eaton]

I pushed a patch for a GUI variable editor:

https://savannah.gnu.org/patch/?8656

This change is the work of a number of people including Rüdiger 
Sonderfeld, Philip Nienhuis, and Michael Barnes.

It seems to work, but I think there is a lot more to be done before it 
is really finished.  But, as I said on the patch tracker, I went ahead 
and pushed this addition now instead of waiting until the patch is 
"perfect" because in my experience, waiting for that will mean that the 
patch will never be pushed.

Currently, when starting Octave with no qt-settings file, I see the 
variable editor window placed to the right of the command window, not 
inside of the tabbed widget that contains the terminal, code editor, and 
doc browser widgets.  This happens even though the initialization of the 
variable editor window appears to me to be the same as for the other 
tabbed widgets.  Can anyone with more Qt experience suggest a fix for 
that so that the default position is the same as the other tabbed widgets?

jwe