CRM-4796 Configure events tabs - detect if user changed form data and warn if they navigate away without saving

Currently users can easily make changes in one of the event configuration tabs and then click another tab without realizing that their data has not been saved. We should detect form data changes and give a warning. I found two potential jQuery approaches for this with a quick net search:

http://stackoverflow.com/questions/807159/detecting-data-changes-in-forms-using-jquery
http://www.elctech.com/articles/dirtyform-watching-for-form-changes-with-jquery