Show user name, and make buttons clearer.
Make registration not accept duplicates, and return user to the registration form. (Displaying the error coming soon.)
Merge remote-tracking branch 'heroku/master'

(Old changes that I made on my desktop and deployed to the heroku server, but not to the github server before I left.

Conflicts:
	todo_tracker/templates/home_base.html
	todo_tracker/views.py