Paint.NET 3.20

This release adds numerous enhancements and tweaks to the built-in effects, a re-organized Effects menu, a new and much easier system for effect plugin development, better error handling for plugins, and the ability to draw Fixed Ratio and Fixed Size selections with the Rectangle Select tool. It also includes the customary list of tweaks and fixes.

* Rectangle Select tool can now draw selections based on a Fixed Size or Fixed Ratio setting.
* The selection combination mode is now accessible from the toolbar (Replace, Add, Subtract, Invert ("xor")).
* The "flood mode" for the Magic Wand and Paint Bucket tool are now accessible from the toolbar (Continuous, or Global).
* Reorganized the Effects menu so that all effects are classified under submenus named Artistic, Blurs, Distort, Noise, Photo, Render, and Stylize.
* Improved rendering quality for the Motion Blur effect.
* Enhanced the Radial Blur effect so that the center of blurring can be chosen, as well as the quality.
* Enhanced the Zoom Blur effect so that the center of zooming can be chosen.
* Enhanced the Bulge distortion effect so that the center of "bulging" can be chosen.
* Enhanced the Frosted Glass distortion effect in several ways: 1) performance has been improved from between 1,000% to 10,000% depending on image size and property settings, 2) the scatter radius can now be set up to 200 pixels, 3) a "minimum" scatter radius can be chosen, 4) a smoothness setting is now available.
* Enhanced the Tile Reflection distortion effect by adding a Quality property.
* Enhanced the Twist distortion effect by 1) allowing counter-clockwise twisting, 2) allowing the size of the twisted area to be configured, 3) allowing the location/center of twisting to be chosen.
* Enhanced the Add Noise effect by adding a "coverage" property.
* New Mandelbrot Fractal and Julia Fractal render effects.
* New IndirectUI system for plugin authors so that they can develop much more sophisticated effect configuration dialogs with a fraction of the amount of work that used to be required.
* If an effect plugin crashes, it is much more likely that Paint.NET will be able to recover from the error.
* The option to restart Paint.NET will then be provided as a recommended course of action.
* If an effect plugin fails to load, or is blocked from loading, then a "View Plugin Load Errors..." item will be added to the File menu which can be clicked on to show the error and/or diagnostic information.
* Improved the cursors for the Magic Wand and Paint Bucket tools.
* Ctrl+Alt+0 now works for View->Actual Size (aka, "Zoom to 100%"), which is a shortcut key that other software uses (e.g., Photoshop).
* Updates are now installed faster by only creating one System Restore point instead of two (it used to implicitly create one for uninstall, then one for the reinstall).
* Lots of little bug fixes.