Copy to clipboard

This adds handy copy-to-clipboard links to the spy and share dialogs. The tooltip changes from "Copy to clipboard" to "Copied!" when the user clicks it. Closes #1528 

![screen shot 2014-10-17 at 3 42 11 pm](https://cloud.githubusercontent.com/assets/1250387/4687101/e09e3674-564e-11e4-8597-5a2bf5b18abb.png)