Show indications for username and password formats

See https://github.com/FreshRSS/FreshRSS/issues/679

app/i18n/cz/gen.php

@@ -27,14 +27,20 @@ return array(
 		'login_persona' => 'Přihlášení pomocí Persona',
 		'login_persona_problem' => 'Problém s připojením k Persona?',
 		'logout' => 'Odhlášení',
-		'password' => 'Heslo',
+		'password' =>  array(
+			'_' => 'Heslo',
+			'format' => '<small>Alespoň 7 znaků</small>',
+		),
 		'registration' => array(
 			'_' => 'New account',  // TODO: translate
 			'ask' => 'Create an account?',  // TODO: translate
 		),
 		'reset' => 'Reset přihlášení',
-		'username' => 'Uživatel',
-		'username_admin' => 'Název administrátorského účtu',
+		'username' => array(
+			'_' => 'Uživatel',
+			'admin' => 'Název administrátorského účtu',
+			'format' => '<small>maximálně 16 alfanumerických znaků</small>',
+		),
 		'will_reset' => 'Přihlašovací systém bude vyresetován: místo sytému Persona bude použito přihlášení formulářem.',
 	),
 	'date' => array(

app/i18n/de/gen.php

@@ -27,14 +27,20 @@ return array(
 		'login_persona' => 'Anmelden mit Persona',
 		'login_persona_problem' => 'Verbindungsproblem mit Persona?',
 		'logout' => 'Abmelden',
-		'password' => 'Passwort',
+		'password' => array(
+			'_' => 'Passwort',
+			'format' => '<small>mindestens 7 Zeichen</small>',
+		),
 		'registration' => array(
 			'_' => 'New account',  // TODO: translate
 			'ask' => 'Create an account?',  // TODO: translate
 		),
 		'reset' => 'Zurücksetzen der Authentifizierung',
-		'username' => 'Nutzername',
-		'username_admin' => 'Administrator-Nutzername',
+		'username' => array(
+			'_' => 'Nutzername',
+			'admin' => 'Administrator-Nutzername',
+			'format' => '<small>maximal 16 alphanumerische Zeichen</small>',
+		),
 		'will_reset' => 'Authentifikationssystem wird zurückgesetzt: ein Formular wird anstelle von Persona benutzt.',
 	),
 	'date' => array(

app/i18n/en/gen.php

@@ -27,14 +27,20 @@ return array(
 		'login_persona' => 'Login with Persona',
 		'login_persona_problem' => 'Connection problem with Persona?',
 		'logout' => 'Logout',
-		'password' => 'Password',
+		'password' => array(
+			'_' => 'Password',
+			'format' => '<small>At least 7 characters</small>',
+		),
 		'registration' => array(
 			'_' => 'New account',
 			'ask' => 'Create an account?',
 		),
 		'reset' => 'Authentication reset',
-		'username' => 'Username',
-		'username_admin' => 'Administrator username',
+		'username' => array(
+			'_' => 'Username',
+			'admin' => 'Administrator username',
+			'format' => '<small>maximum 16 alphanumeric characters</small>',
+		),
 		'will_reset' => 'Authentication system will be reset: a form will be used instead of Persona.',
 	),
 	'date' => array(

app/i18n/fr/gen.php

@@ -27,14 +27,20 @@ return array(
 		'login_persona' => 'Connexion avec Persona',
 		'login_persona_problem' => 'Problème de connexion à Persona ?',
 		'logout' => 'Déconnexion',
-		'password' => 'Mot de passe',
+		'password' => array(
+			'_' => 'Mot de passe',
+			'format' => '<small>7 caractères minimum</small>',
+		),
 		'registration' => array(
 			'_' => 'Nouveau compte',
 			'ask' => 'Créer un compte ?',
 		),
 		'reset' => 'Réinitialisation de l’authentification',
-		'username' => 'Nom d’utilisateur',
-		'username_admin' => 'Nom d’utilisateur administrateur',
+		'username' => array(
+			'_' => 'Nom d’utilisateur',
+			'admin' => 'Nom d’utilisateur administrateur',
+			'format' => '<small>16 caractères alphanumériques maximum</small>',
+		),
 		'will_reset' => 'Le système d’authentification va être réinitialisé : un formulaire sera utilisé à la place de Persona.',
 	),
 	'date' => array(

app/views/auth/register.phtml

@@ -1,19 +1,14 @@
-<?php
-    /* TODO list
-     *   - Show help for username and password formats
-    */
-?>
 <div class="prompt">
     <h1><?php echo _t('gen.auth.registration'); ?></h1>
 
     <form method="post" action="<?php echo _url('user', 'create'); ?>">
         <div>
-            <label class="group-name" for="new_user_name"><?php echo _t('gen.auth.username'); ?></label>
+            <label class="group-name" for="new_user_name"><?php echo _t('gen.auth.username'), '<br />', _i('help'), ' ', _t('gen.auth.username.format'); ?></label>
             <input id="new_user_name" name="new_user_name" type="text" size="16" required="required" maxlength="16" autocomplete="off" pattern="[0-9a-zA-Z]{1,16}" />
         </div>
 
         <div>
-            <label class="group-name" for="new_user_passwordPlain"><?php echo _t('gen.auth.password'); ?></label>
+            <label class="group-name" for="new_user_passwordPlain"><?php echo _t('gen.auth.password'), '<br />', _i('help'), ' ', _t('gen.auth.password.format'); ?></label>
             <div class="stick">
                 <input type="password" id="new_user_passwordPlain" name="new_user_passwordPlain" required="required" autocomplete="off" pattern=".{7,}" />
                 <a class="btn toggle-password" data-toggle="new_user_passwordPlain"><?php echo _i('key'); ?></a>

app/views/auth/reset.phtml

@@ -16,7 +16,7 @@
 		</p>
 
 		<div>
-			<label for="username"><?php echo _t('gen.auth.username_admin'); ?></label>
+			<label for="username"><?php echo _t('gen.auth.username.admin'); ?></label>
 			<input type="text" id="username" name="username" size="16" required="required" maxlength="16" pattern="[0-9a-zA-Z]{1,16}" autofocus="autofocus" />
 		</div>
 		<div>