Help browser account saving with accounts-ui login/signup forms #9442
`accounts-ui-unstyled` currently uses `<div />`'s to hold its login/signup forms, as well as `<div />`'s to represent the login/signup buttons in the form. By not using proper `<form />` and `<button />` elements, certain browser's do not notice incoming login/signup requests, and therefore do not trigger their built in "would you like to save your user/password" functionality. This commit adjusts the `accounts-ui-unstyled` login/signup form to use proper `<form />` and `<button />` elements, allowing most (Chrome, Firefox, IE - Safari will recognize the request when a user attempts to leave the page) browsers to recognize incoming login/signup requests. Fixes #1746.
@benjamn Normally I would consider this a package patch, but I just thought of something. Since we're changing some of the HTML elements used by the login/signup form, if anyone is styling based on explicit HTML element names instead of using the