I had to go to win32 hell and back to pull this off but it finally works!!

my modeling tool now has a custom title bar! while still also supporting resizing, title bar dragging, and all those nice window features! this is nontrivial for some reason!!

@acegikmo I don't think people appreciate exactly how non-trivial all the windowing stuff is! Major props for getting it working!

@tojiro @acegikmo

Not just windowing stuff. I never figured out how to get the coordinate to the text cursor so that I could open a code completion dialog. I spent probably a week trying to figure that out.