Bug fix for translation class, DB IO connection error set fix

- The translation file reader did an isset on a set variable insetad of
checking if the variable is zero and so never started the translation
system
- The DB IO connection not set was wrongly set. If the connection failed
it is not TRUE and else FALSE. There is a new internal method
getConnectionStatus to query this status it returns TRUE/FALSE depending
if the connection failed

- Update the l10n test page with proper translation tests
  - init OK
  - show current lang/file
  - translation test
  - switch language test

www/admin/namespace_test.php

@@ -17,6 +17,9 @@ echo "DIR: ".DIR."<br>ROOT: ".ROOT."<br>BASE: ".BASE."<br>";
 $lang = 'ja_utf8';
 $base = new CoreLibs\Admin\Backend(DB_CONFIG, $lang);
 ob_end_flush();
+if ($base->getConnectionStatus()) {
+	die("Cannot connect to database");
+}
 
 print "Start time: ".$base->runningTime()."<br>";
 print "ByteStringFormat: ".$base->ByteStringFormat(1234567.12)."<br>";