Handles the "Find/Repair Any Errors" functionality - finds errors and allows the admin to repair them.

• Requires the admin_forum permission
• Sets the admin index to maintain_forum
• Accessed at index.php?action=repairboards
• Fix errors routine requires a valid session id (ie index.php?action=repairboards;fixerrors;sesc=session_id)
• Checks for the following errors: topics with an ID of 0, messages with an ID of 0, messages with nonexistent topics, topics that don't have any messages, topics with invalid ID_FIRST_MSG (ID of the first message in the topic), topics with invalid ID_LAST_MSG (ID of the last message in the topic), topics with an invalid numReplies (number of replies), topics with nonexistent boards, boards with nonexistent categories, messages with nonexistent members (ie the member who posted the message doesn't exist) and boards with nonexistent parents.
• Calls CreateSalvageArea if needed