Fixes toolbar bug, adds selector support for element.

[skoczen]

Hello,

Thanks for writing this library - it's been my choice out of dozens I reviewed. Great work!

This is a small pull request with a couple fixes:

• Fixes toolbar:false option - both documentation and the code were broken.
• Adds element-query support to the element option, so the example in the README is possible.
• Adds an AUTHORS file, as is standard - and something I've found very helpful in my own open source projects.

Please let me know if you have any questions, and thanks again!
-Steven