Drupal 6 update patch

This patch updates the module for Drupal 6, fixes some minor issues and tidies up whitespace, documentation and style to meet drupal's style guide, standards and best practices. I also left 3 @todos in where changes need to be made to implement drupal's permissions system to determine whether to track the user or not in a simpler way.

There may be an issue with robotreplay_verification_page() since I couldn't get robotreplay.com to verify http://drupal.geek.nz/I7CthvaI.txt. It might be an issue with robotreplay.com