Encode semicolons in full names for the new OpenID server

The new OpenID server doesn't encode semicolons in the redirection back to the relying party. For example, a user with a full name of Hello;

&openid.ext1.fullname=Hello;

If the RP treats semicolons as separators (for example, Play!), then this won't pass signature validation. It should be:

&openid.ext1.fullname=Hello%3B