Start user management.

Need to:
- Create a user class
- Add default password/login lengths
- Registration
See https://flask-login.readthedocs.org/en/latest/#your-user-class
change name of login length config
build user class in sqlalchemy
still need to handle bad logins
need to make a new template for login form.
login form
create schema in register function?
second password field is password
handle user already existing
try a different errors approach
proper errors
wrong url_for
fix errors and url_for in login function
flask namespace
more flask namespace
if we can't connect to database, we should redirect to registration page
if we can't look up the user, return None
formatting based on Tyler's suggestions
add footer
add footer