AMD Support

These changes make it possible to use this library with require.js

The issue is that one of the 3rd party libraries that is included in the build tries to call define:
https://github.com/warpech/jquery-handsontable/blob/master/dist/jquery.handsontable.js#L9680

Require.js treats the value passed by this call as the Handsontable object instead of using window.Handsontable.

I've include proper support for AMD so that shimming is no longer required. Hope this helps.