Redis now available as datastore for users for cb_server

- Added package.json for easy "npm install" installation
- If USE_REDIS=T in the env, cb_server will use Redis for its
  user records.
- bcrypt support for password one-way hashing
- Set HOMEREC=0 in cf/cbconfig so that user records are stored
  by Unix-CB in "recs" directory instead of individual Unix home
  directories, since cb_server doesn't create actual Unix accounts