Provide email address verification feature (#2481)

* Add an email field to the profile page

I reuse the `mail_login` from the configuration. I'm not sure if it's
useful today (I would say it was used when Persona login was available).

A good improvement would be to rename `mail_login` into `email` so it
would be more intuitive to use.

* Add boolean to the conf to force email validation

This commit only adds a configuration item.

* Add email during registration if email must be validated

* Set email token to validate when email changes

* Block access to FreshRSS if email is not validated

* Send email when address is changed

* Allow to resend the validation email

* Allow the user to change its email while blocked

* Document the email validation feature

* fixup! Allow the user to change its email while blocked

* tec: Autoload PHPMailer lib

* Validate email address format

* Add feedback on validation email resend action

* Allow to logout when user is blocked

* fix: Change default email "from"

* Reorganize i18n keys

* Complete all the locales with default english

* Hide sidebar (profile page) if email is not validated

* Check email requirements on registration

* Allow admin to specify email when creating users

* Don't check email format if value is empty

* Remove trailing comma in userController

Co-Authored-By: Alexandre Alapetite <alexandre@alapetite.fr>

* Set PHPMailer validator to html5 before sending email

* fixup! Remove trailing comma in userController

app/Controllers/authController.php

@@ -205,6 +205,7 @@ class FreshRSS_auth_Controller extends Minz_ActionController {
 			Minz_Error::error(403);
 		}
 
+		$this->view->show_email_field = FreshRSS_Context::$system_conf->force_email_validation;
 		Minz_View::prependTitle(_t('gen.auth.registration.title') . ' · ');
 	}
 }