Help browser account saving with accounts-ui login/signup forms

[hwillson]

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 browsers (Chrome, Firefox, IE - Safari will recognize the request when a user attempts to leave the page) to recognize incoming login/signup requests.

Fixes #1746.

[benjamn]

This should be a patch update for the accounts-ui-unstyled package, right?

[hwillson]

@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 class/id selectors, this could be a backwards incompatible change. So if someone is adding custom styles like div.login-form { ... } for example, their styles will break now that div has been replaced with form. In the name of progress however, we should still consider moving ahead with these changes, but I'll add a History.md entry explaining the potential backwards compatibility issues. Because of this, maybe we should tie these changes to release 1.6.1 (giving people a better chance of seeing this potential issue in the change log)?

[abernix]

That's a good point @hwillson. It sounds reasonable to me to tie this to 1.6.1 — which means it would earn a minor version bump, in addition to a minor version bump on accounts-ui which depends on it, correct?

(Otherwise this LGTM.)

[hwillson]

Minor versions bumped - thanks @abernix!