Updated Save&Close and Save&AddAnother buttons, CORE-557

A couple of things here:

1. Please declare all variables used in a function at the top. Line 635 should be something like `var ajd, save_close_btn, save_addmore_btn, modal_backdrop;`
2. I'd prefer `if (el.is(':not(.disabled)')) {` to be `if (el.is('.disabled')) {`. The new if statement should just return immediately so that the whole function will have one indentation less.
3. `$(this.element).find` can be `this.element.find`.