Design inconsistencies with form validation

[sguzik]

When a users attempts to submit a form that includes incomplete required fields, fields are highlighted inconsistently. Short text fields highlight with a red border, but email fields and long text areas do not (see screenshot below).

When a user attempts to submit a form with an invalid email address, an alert appears under the submit button ("There are one or more errors with your responses. Please see above."; screenshot below). That alert only appears when the email address is invalid, not when it is missing entirely. Additionally, that alert only appears for an invalid email address, not any other failed validation.

cc @jtnelson