Fully review spec doc and check against this code, and pull out protocol part

[mitra42]

• [x] See #64 for stuff not done
• [x] See #63 for minor (naming change level) discrepancies
• [x] Need to handle the naming consistency request of Jamison - part of #63
• [x] Check through remaining comments in doc
  • [x] Waiting on discussion of Alice updates with @jmday
  • [x] Waiting on review of signon by @jmday and @danaronson
• [x] Move to fresh doc
• [x] Link from old BCT spec (deleting duplication)
• [x] Review old BCT spec for other things to pull out - e.g. security analysis

[mitra42]

All done or has own issues