Merge branch 'readme-update'
Create User model and add paired_code_id to Code

Also add method for generating a code string, and for creating a pair of
linked codes.
Add temporary action to create two linked code pairs
Working flow of user logging in and submitting code

This now uses ActiveRecord models and relationships to link codes and
users.
Namespace Code and User model

Originally merged from a separate branch, but turned into a single commit
for log clarity.
Very basic error checking and login formatting

Redirect the user back to the code submission if they enter an unknown
code. Also, add a bit more HTML formatting to the login.
Merge branch 'master' of git://github.com/joonty/ppwm-matcher into joonty-master

Conflicts:
	models/code.rb
Merge branch 'joonty-master'