Store the XML for deadlocks in the repository

This would enable the following potential additional features:

• A deadlocks tab that would show the SQL involved in deadlocks along with a count of its appearance in deadlocks during a specific timeframe (along with a second counter showing how many times it was a deadlock victim).
• An email alert that would trigger on each deadlock and either include the XML for the deadlock in the body of the alert email, or as an attachment) to the email, or a link that would display it when clicked.