Allow closing dialogs via OS "window close" button

[apocalyptech]

There's various dialogs which don't close when the user hits the OS "window close" button -- have to use the Java-provided "OK" button or the like. Specifically:

• Changelog
• Uninstall
• Settings
• INI Tweaks
• Legacy Hex Edits
• What Are Profiles?
• Confirm action without save dialog
• Probably others

The dialogs were honestly probably created like that more-or-less by default. We often want the result of one of the given buttons passed back. But there's mostly no good reason not to figure out having a default action fire when the dialog is told to close, instead of just denying the request. The behavior should probably ideally be:

1. If the dialog has a "Cancel" button, send "Cancel" back
2. If the dialog just has a single button which is "OK", send OK back
3. In the absence of OK or Cancel, continue to deny the window-close request.

In terms of our newish AdHocDialog class, we've got four ButtonSets:

• YES_NO - No default, continue to deny the request
• YES_NO_CANCEL - Default is Cancel
• OK - Default is OK
• OK_CANCEL - Default is Cancel

[apocalyptech]

Okay, yep, this turned out to be a pretty easy one. All instances where it wasn't working were using AdHocDialog, so adding support in there fixed all these up. Since we're using that dialog very heavily throughout the app, I expect this probably took care of nearly all cases.