Add the username and password to the QS

Picked up by the session manager and used in cases where we use a
session based login
Session based logins now possible

username and password now blanked out, like token is
Instead of dying with a message if we don't have hardcoded values,
redirect to the index page with a QS which we pick up to show a login
screen
If we have REQUEST token or username vars (via GET or POST), set the
values to that. POST is received via the login form submission, GET is
received via the querystrings on the iFrames and forms called
Restablish session vars for these if we have them
Session login screen added

If we have the sessionLogin QS var, show the login screen, otherwise
show ICErepo
Pass the username and password values through in the QS to the contents
iFrame