comment out display list debug window

comment out the display list debug window in the QT version
because it's not maintained and currently causes compilation
errors because it was not updated to deal with the new GPU
backend
Merge pull request #6927 from Bigpet/displwnd

comment out display list debug window
Add some additional ABI call funcs, cleanup.

ImmPtr is cleaner, let's use it rather than ugly casts.
Clean up a few more ImmPtr() cases.