Formatted source code.
Using DB::count function in print_vocab_jlpt_levels. Refactored get_weighted_readings function to use PDO and removed user_id parameter as it is not being used. Formatted source code.
Refactored get_set_weighted_readings function to use PDO and removed user_id parameter as it is not being used. Formatted source code.
Refactored get_random_readings function to use PDO. Formatted source code.
Refactored various functions to use PDO (and renamed to be PSR compliant). Formatted source code. Added missing jquery.corner.js.