Implement as UMD

[dalaidunc]

trafficstars

UMD is a way of declaring this library so that it will work nicely with modern javascript modules and webpack etc.

(Currently I had to hack this library into webpack).

More info: https://github.com/umdjs/umd/blob/master/templates/jqueryPlugin.js

And for anyone it might help, current workaround: https://65535th.com/jquery-plugins-and-webpack/