Wrong parameters for hook_form_alter()

Issue Summary

The function signature for implementation of hook_form_alter() has changed in Drupal 6 (see http://api.drupal.org/api/function/hook_form_alter/6). The inxmailprofessional_subscription module hasn't been updated, which causes the "Newsletter" checkbox not to appear on registration and contact forms.

The patch below fixes this issue for inxmailprofessional_subscription_form_alter(), as well as the formatting for submit handlers. There might be other instances of hook_form_alter() in the various inxmailprofessional modules that need to be updated as well.