Added support for use with webpack

[ruscoder]

No description provided.

[blueimp]

Could you elaborate why the current version of this project doesn't already fit in with webpack?

[blueimp]

Closing for now, as this will need a rebase on the latest changes.

[micky2be]

I currently cannot require submodule of your loader using webpack.
For example using import loadImage from 'blueimp-load-image/js/load-image-orientation';

This PR fixes the problem.

[blueimp]

Thanks @ruscoder, I've finally merged this, thanks to @micky2be's rebase.