GCI-42: redesign of edit email addresses widget

Ticket: https://issues.openmrs.org/browse/GCI-42
Melange task: http://www.google-melange.com/gci/task/view/google/gci2014/5270481909317632

I moved the widget code into a new file, edit-email.ejs. Also, I wasn't sure if the "Add Another" link was supposed to toggle the email input field, but I implemented it similar to the password-edit toggle in my [previous PR](https://github.com/openmrs/openmrs-contrib-id/pull/43).