Why the MIT / Old-style BSD license appeared in LEGAL?

[voxik]

Can somebody elaborate why #610 introduced MIT / Old-style BSD?

Looking into history, I can see that up until f53a0e3, there used to be included prototype.js, licensed under MIT, but that is history for 5 years. Is there anything else?

What would be the reason for stating Old-style BSD is complete mystery to me.