Customizable text field name and descriptive text

This patch file includes kaushik_sarkar's 5.x update, as well as the following:

Have added fields to the Admin Settings function to allow for customizable text field name and descriptive text. Edited the code injection function to make use of these new variables.

One issue has come up, though:

* warning: Missing argument 2 for variable_get(), called in C:\xampp\xampp\htdocs\modules\regcode\regcode.module on line 138 and defined in C:\xampp\xampp\htdocs\includes\bootstrap.inc on line 369.
* warning: Missing argument 2 for variable_get(), called in C:\xampp\xampp\htdocs\modules\regcode\regcode.module on line 141 and defined in C:\xampp\xampp\htdocs\includes\bootstrap.inc on line 369.

Both of those calls seem to be correct, though:

case 'register':
// Inject the registration code field into the registration form.
$form['regcode_code'] = array(
'#type' => 'textfield',
'#title' => variable_get('regcode_title', ''),
//'#default_value' => variable_get('regcode_codes', ''),
'#required' => TRUE,
'#description' => variable_get('regcode_desc', '')
);
return $form;

Thanks for your attention to this. :)