Add Croatian (hr) translation

Add complete Croatian translation for Adminer, including all strings
in adminer/lang/hr.inc.php, plural forms support in lang.inc.php,
and Croatian descriptions and translations for all plugins.

plugins/edit-foreign.php

@@ -46,5 +46,6 @@ class AdminerEditForeign extends Adminer\Plugin {
 		'pl' => array('' => 'Wybierz klucz obcy w formularzu edycji'),
 		'ro' => array('' => 'Selectați cheia străină în formularul de editare'),
 		'ja' => array('' => '外部キーを編集フォームで選択'),
+		'hr' => array('' => 'Odabir stranog ključa u obrascu za uređivanje'),
 	);
 }