Login page connected

Added login page. Made it a requirement that users be logged in to
create reports. To disable this (for testing purposes) disable line 46:
@tornado.web.authenticated by adding a # in front of it
(#@tornado.web.authenticated). This will allow you to go between all
pages easily. type /login to go to login page
Connected login page

Added Login option to index.html and linked it to the mainController.
Now, clicking login will take you to the login page.