Replace CodePress with CodeMirror #37
Remove codepress folder #37
Admin CP PIN #38

Adds an optional secret PIN to the Admin CP login
Fixes bug #39 - related to feature #38

$config['security_pin'] should obviously be $config['secret_pin']
Fixes bug #40

Reverted back to functions_warnings.php
Fixes possible SQL error in checktables.php
Fixes #2180 PHP errors when attempting to send Mass Mail