I've written a short article about how to create your self-signed driver package for the Usb Ir Toy. I've also published the updated signed files on Github. Here's the summary:
1. Get the inf-file in order (and I put the Usb Ir Toy repository on Github)
2. Generate certificates
3. Trust the certificate
4. Install the new driver
This doesn't require the test mode or disabling driver signing. I also included the certificates and updated driver files on the Github repo so it should be rather easy for someone to install it.
Here's the link to the full article: https://haukcode.wordpress.com/2015/04/21/how-to-create-a-signed-windows-8-driver-for-usb-ir-toy/