Plugin: Toolbar

Hi Lea -

For a recent project we wanted an easy way for our users to copy the code on our pages. Thus I've created a new plugin that allows users to copy code to the clipboard and open a new window with the raw code (for easy copying, printing, etc.) The plugin depend on the robust [ZeroClipboard](http://zeroclipboard.github.io/ZeroClipboard/) library (used here at GitHub) for users to copy to their clipboard. However if it is not included, the code will simply not render the "copy to clipboard" link. I've also attempted to make sure the styling works for all of the available themes, although minor tweaks could be made for better visibility for the "funky" theme.

Normal:
![toolbar_light](https://f.cloud.github.com/assets/950141/861213/cf584f76-f5c9-11e2-9979-8704e69096ce.png)
Twilight:
![toolbar_dark](https://f.cloud.github.com/assets/950141/861212/cf4cbfda-f5c9-11e2-9323-0a6442008603.png)
Funky:
![toolbar_funky](https://f.cloud.github.com/assets/950141/861232/6404cad2-f5ca-11e2-910d-87e1864af5f6.png)

I've also hosted the [plugin demo page](http://dev.misterphilip.com/prism/plugins/toolbar/) for easy viewing & testing. 

Please let me know if you have any questions or feedback!

Best,
Phil