Switch to using FT FastClick for eliminating touch delay

[FT FastClick](https://github.com/ftlabs/fastclick) is probably the most actively supported polyfill for eliminating the 300ms delay experienced on some mobile browsers.

I think it would be good for MPB to switch to using it at this point, especially since browser vendors are now working to eliminate the delay. FastClick is pretty proactive in not attaching listeners when it isn't needed.