Add 1 month indication for "keep me logged in"

.prompt .form is also now larger

See https://github.com/marienfressinaud/FreshRSS/issues/465

app/i18n/en.php

@@ -3,7 +3,7 @@
 return array (
 	// LAYOUT
 	'login'				=> 'Login',
-	'keep_logged_in'		=> 'Keep me logged in',
+	'keep_logged_in'		=> 'Keep me logged in <small>(1 month)</small>',
 	'login_with_persona'		=> 'Login with Persona',
 	'logout'			=> 'Logout',
 	'search'			=> 'Search words or #tags',

app/i18n/fr.php

@@ -3,7 +3,7 @@
 return array (
 	// LAYOUT
 	'login'				=> 'Connexion',
-	'keep_logged_in'		=> 'Rester connecté',
+	'keep_logged_in'		=> 'Rester connecté <small>(1 mois)</small>',
 	'login_with_persona'		=> 'Connexion avec Persona',
 	'logout'			=> 'Déconnexion',
 	'search'			=> 'Rechercher des mots ou des #tags',

p/themes/Dark/dark.css

@@ -570,7 +570,7 @@ a.btn {
 }
 .prompt form {
 	margin: 10px auto 20px auto;
-	width: 180px;
+	width: 200px;
 }
 .prompt input {
 	margin: 5px auto;

p/themes/Flat/flat.css

@@ -551,7 +551,7 @@ a.btn {
 }
 .prompt form {
 	margin: 10px auto 20px auto;
-	width: 180px;
+	width: 200px;
 }
 .prompt input {
 	margin: 5px auto;

p/themes/Origine/origine.css

@@ -598,7 +598,7 @@ a.btn {
 }
 .prompt form {
 	margin: 10px auto 20px auto;
-	width: 180px;
+	width: 200px;
 }
 .prompt input {
 	margin: 5px auto;

p/themes/Screwdriver/screwdriver.css

@@ -665,7 +665,7 @@ ul.feeds.active{
 }
 .prompt form {
 	margin: 10px auto 20px auto;
-	width: 180px;
+	width: 200px;
 }
 .prompt input {
 	margin: 5px auto;