CiviEvent: Replace New Event Wizard with Tab Interface

The New Event wizard interface forces users to step through a series of forms in a fixed order. This is unnecessary for many use cases. We can simplify the user experience and allow them to move around the various sections at will by replacing the wizard with a Tab interface. Once the first "tab" (Event Information and Settings) is saved, all the other tabs are accessible by clicking.

You can see an example of this style interface on the PHPList demo (thanks to Xavier Dutoit for pointing the way here):

http://demo.phplist.com/lists/admin/
Login: admin
pwd: phplist
http://demo.phplist.com/lists/admin/?page=send&id=17

We'll support users who want to proceed in a fixed order by providing a Next button in addition to the Save Changes button.