ShowHide: minimize async dance if values are known
ShowHide: code comments and reorg
show_hide_example: better default style
I think we're rocking' the CSS3 animations
ShowHide: better handling of edge cases

...I'm really glad I have a robust test setup
a whole set of CSS3 transition animations
ShowHide: private class to the bottom of the file
ShowHide is back being 100% static
SpinEffect: Fun 3D transform effect
ShowHide: tolerate explicit null duration
show_hide_example: remove some cruft