nginx blocks access without cookie, add static unprotected login page, REST call to set cookie on login success, redirection from top of namespace to the login page
add files missing from last commit
use a auth cookie to login instead of a constant string, and set it site-wide
do password hashing, generate random passwords
turn off nginx debug logging
add missing file, the static html login page
move baseURL from Main to Config, use it in LoginRest too
add ssl support: when server is publicly available generate a cert on startup, and direct nginx to use it.  also remove extra slashes from login page redirects.
make the initial redirection to the start page (either login or the app itself) and the nginx authorization gate depend on the --public-server option
remove unused command-line option --no-password (should implement it later).  use 127.0.0.1 for the origin host to avoid CORS complaints from ipython.
mark the cookie as secure (it should only be sent over https)
Merge pull request #317 from twosigma/public-server

Public server option