Add eyedropper to Chrome

[dumbmatter]

Chrome's actual color picker widget has an eye dropper to let you pick any color. Chrome actually has an API to let you easily add that functionality https://developer.mozilla.org/en-US/docs/Web/API/EyeDropper - although it won't work in any other browsers, unfortunately. Might still be worth adding, you can do feature detection to decide whether to show it or not.

[jaywcjlove]

@dumbmatter Upgrade v2.2.0