Support for ISNI on copyright page

[dormerod]

There seems to be a relatively new thing called an ISNI: http://www.isni.org/

From what I gather, the idea is to have a unique identifier for publishers, authors, artists etc (like an ISBN, but for people and other entities). I don't know if it's popular or if it will take off, so I'm just noting it here for later. This is a low priority.