don't depend on drag&drop in demo

This enables the demo for those of us who don't have a desktop and can't "drop" anything on our browser windows.
This is a quick fix, you might not want to merge this code-duplicating version, but it works for me.
(I'm sad the libopenmpt version does work better than the libxmp one. :P )

On another note, your License file isn't actually the [X11](http://directory.fsf.org/wiki/License:X11), but the [Expat](https://directory.fsf.org/wiki/License:Expat) "MIT" license.