Hey Everyone,

I've made some improvements to the fancy imshow widget and the ColorMixer.

The ColorMixer now supports a brightness function.

And the fancy imshow widget now includes labeled sliders, a function
selector combo box, a commit button and a revert button.

Basically, changes will persist between combo-box selections, only if
you commit changes. Otherwise, the image is reverted to the most
recent commit state.

The revert button does a hard reset to the very original image.

Please grab everything from my io branch and give it a run through.

I think the next thing I will add is hsv support and a histogram under
the image.

Let me know what else you want!