Devise bug

so when you upgrade devise, you need to change some stuff in the emails it sends out, otherwise the confirmation tokens won't work.  This branch fixes that problem.

Unfortunately there is another problem, probably related, which I have raised an issue about over on the Devise project: https://github.com/plataformatec/devise/issues/3009

This PR improves the situation somewhat over what was there before, in that it is at least possible to sign up now.  But it is still kinda broken in that after confirming your account the user experience is abominably broken, and signing in is far more of an adventure than it should be.