Make screenshot tests work with tiling window managers.

[dolda2000]

On some window managers, notably tiling ones, a resizable window will automatically be resized from its default size, which makes the screenshot comparison tests fail. Making the JFrame non-resizable fixes the issue.

[SWinxy]

Hi @dolda2000. Which platforms is the test failing on because it's resizable?

[dolda2000]

@SWinxy My particular configuration is StumpWM on X11/Linux, but I'd imagine most tiling window managers would behave the same.

[SWinxy]

I'm having quite the issue installing StumpWM on my VM. The lisp interpreter the GitHub README gives an error. I've never used lisp before, but I'll give it another shot another day.

[dolda2000]

If you want another tiling WM, you can probably try ratpoison instead. I haven't specifically tried this case on it, but I know how it works from having used it previously, and I'd be extremely surprised if it doesn't elicit the same problem. It's an ordinary, standalone C program, so it shouldn't give too much trouble.