Promising new Qt GUI

[Jordi Gutiérrez Hermoso]

And yes, it's hooking onto the readline idle loop too:

     https://github.com/jacobdawid/Quint

And some promising screenshots:

     http://www.pic-upload.de/view-9501420/screenshot_quint.png.html

This looks just like what the doctor ordered. A brief chat in #octave
with Jacob Dawid, the author, has revealed that he's using a
PendingRequest class that allows very flexible communication with the
Octave process (say, from a plotting window or a workspace window).
He's amenable to the idea of the code being worked into the Octave
sources, of releasing it under the GPL, following GNU coding
guidelines and all that.

I'm excited about this one. I think we finally have a winner. There
are a few problems, which is why Jacob was asking in IRC, but the
overall direction looks correct. I'll let Jacob (cc'ed here) explain
himself more.

- Jordi G. H.