Fullscreen visualization for "ED visualize mode"

[LFBFerreira]

It would be nice to be able to make the debug visualization window fullscreen, sometimes just to show off, other times for debug.

I tried doing that on the ed/src/helpers/visualization.cpp file, where the window is being updated, but i could not find the point where it is created, so i could add the flag CV_WINDOW_NORMAL.

Maybe i overlooked something