Putting the set password back into add_email_address and verify_email_address

* user.js: Update verifyEmail and verifyUser to take a password.
* network.js: Update completeEmailRegistration and completeUserRegistration to take a password.
* Replace verify_email_address.js and add_email_address.js with a single verify_secondary_address.js to reduce duplication.
* Update the templates.
* Bring back verify_email_address and add_email_address templates, but remove the verify password field.
* To dom-jquery, add show, hide functions.