EMS USB Adapter Support.

So stepmania 3.9 (The old version, not the new one with the terrible theme)
picks up the adapter automatically, to a point where I don't even need to go into config.

Stepmania 5 doesn't pick anything up, can someone please try and include this into the next build release?

Can you provide more information? For example:

What operating system are you running? Windows? Mac OS X? Linux?
What version of SM5 are you using?
Can you include a link to the adapter you are using? I think it's this, but I'm not sure.
What does the adapter register in SM3.9 as? I'm not familiar with SM3.9, but it hopefully has a Configure Input like SM5 that will tell you what input sources there are.

Additionally, you may find this thread helpful. It discusses getting a EMS USB adapter to work with SM5 by using a USB hub. ...which is odd, but maybe worth trying.