Paint.NET 3.22

This release fixes a few minor bugs and adds a new, much-needed Reduce Noise effect.

* New: "Reduce Noise" effect.
* Changed: Ctrl+W will now close Paint.NET if zero images are open.
* Fixed: In Windows XP, when launching web content, sometimes Internet Explorer was used instead of the user's chosen default browser.
* Fixed: The Unfocus effect was not handling alpha values properly.
* Fixed: The Brightness / Contrast adjustment was only displaying its text in English.
* Fixed: The /auto parameter for the installer now correctly allows for an automated installation. This was inadvertently broken in 3.20.