commented error reporting
fixed spelling mistake
uses str_shuffle and substr to generate short URL code
Changed redirect_uri for Facebook login to login.php instead of account.php. This seemed to have fixed the problem causing users to have to login twice with Facebook.
updated README.md
Changed redirect_uri for Facebook login to login.php instead of account.php. This seemed to have fixed the problem causing users to have to login twice with Facebook.
Updated Facebook PHP SDK to v4
Updated README.md
added PHP v5.4 and mbstring to requirements
Updated README.md