Address isssues raised by Robert Ransom.

His email to the CFRG list:
  http://www.ietf.org/mail-archive/web/cfrg/current/msg04836.html
Merge branch 'master' of github.com:/seanturner/draft-turner-thecurve25519function

Conflicts:
	draft-turner-thecurve25519function.md