Revert modify server and add mode in url

mode of experiment gets passed from ad server when subject is sent to
server, then is passed through pages of experiment until the end. Works
locally with "mode=debug", can be tested further once ad-server changes
go live.
change logic of where "mode" sends people for complete route

Now the catch-all case is local "/complete", and people are only sent to
the ad server if mode is "sandbox" or "live". (before, sending people to
the live ad server was the "else" case, so any gibberish mode string
would send them there).
switch to gnureadline
Enable easy ad and api server debugging via config
Stop restarting server on mode change
fix indexing error in insert_mode
Print external URL when using debug --print-only

- Using the --print-only option implies that the user is on a remote
  server, so providing a localhost URL is unhelpful.
Revert "Enable easy ad and api server debugging via config"

This reverts commit 7349612fc9b64afc383cf5854c87306402f126d8.
Merge dev updates
Remove sandbox from server.startup calls
require a newer version of psutil on install

addresses issue #93
Merge branch 'de-modeify-server' into dev