feat aup field for account creation

See merge request rc/self-reg-form!14

2. send checkbox value instead of a hardcoded value

2. added new function check() to enable/disable submit button based on status of checkbox

Fixed redir issue

See merge request rc/self-reg-form!13

Fix web text

See merge request rc/self-reg-form!12

2. fixed overlay message text
3. fixed error message broken href tag

 -  Issue: in case referrer was null, app redirected to /None
 -  Fix: in case of redir value in request, set session to redir value
         else, set session to default referrer (from vars.py))

fixed email href to support@listserv.uab.edu

See merge request rc/self-reg-form!11

removed overlay off due to wait

See merge request rc/self-reg-form!10

removed hard-coded value

See merge request rc/self-reg-form!9

added flask-cors and used allow cross_allowed_origins to fix the issue seen on prod cluster (400 CORS error)

made UI changes to the app

See merge request rc/self-reg-form!8

sending text message for welcome message, error message and cancel message as a variable from messages.py