Rely on iconv and symfony/polyfill-*

Author: nicolas-grekas

Command/TranslationDebugCommand.php

@@ -240,7 +240,7 @@ private function sanitizeString($string, $length = 40)
     {
         $string = trim(preg_replace('/\s+/', ' ', $string));
 
-        if (function_exists('mb_strlen') && false !== $encoding = mb_detect_encoding($string)) {
+        if (false !== $encoding = mb_detect_encoding($string, null, true)) {
             if (mb_strlen($string, $encoding) > $length) {
                 return mb_substr($string, 0, $length - 3, $encoding).'...';
             }

composer.json

@@ -24,6 +24,7 @@
         "symfony/event-dispatcher": "~2.8|~3.0.0",
         "symfony/http-foundation": "~2.4.9|~2.5,>=2.5.4|~3.0.0",
         "symfony/http-kernel": "~2.8",
+        "symfony/polyfill-mbstring": "~1.0",
         "symfony/filesystem": "~2.3|~3.0.0",
         "symfony/routing": "~2.8|~3.0.0",
         "symfony/security-core": "~2.6|~3.0.0",
@@ -40,7 +41,7 @@
         "symfony/css-selector": "~2.0,>=2.0.5|~3.0.0",
         "symfony/dom-crawler": "~2.0,>=2.0.5|~3.0.0",
         "symfony/finder": "~2.0,>=2.0.5|~3.0.0",
-        "symfony/intl": "~2.3|~3.0.0",
+        "symfony/polyfill-intl-icu": "~1.0",
         "symfony/security": "~2.6|~3.0.0",
         "symfony/form": "~2.8",
         "symfony/expression-language": "~2.6|~3.0.0",