Some hooks and form handlers have not been updated for Drupal 6

Issue Summary

This patch corrects the following issues:
- $may_cache is no longer used in hook_menu()
- the $form_id, $form_values parameters have gone away in favour of $form and &$form_state (the data previously in $form_values is now stored $form_state['values'])
- The submit form has been changed to use a submit button instead of system_settings_form() as the module has its own submit function that sets the variables

Misc. other coding style changes as per recommendations by the Code Review module
- Eliminated use of tabs in favour of two spaces
- Empty lines should not be indented