Convert more menu entries to control arrays

The "natural" filters, in this case
Update thank-you list to include JH
Improved comments and attribution
Switch to a higher-quality interpolation mechanism

My old bilinear shortcut doesn't cut it on these new distort transforms
- so I'm giving in and using a traditional interpolation system.
Slightly slower, but much better results on certain distorts.
Improve new distort tool layouts
New pinch-and-whirl distort tool