Updates for language auto detect, fixes for PHP 7.4

There was a bug in ther SQL interface class where the folder was just
called "Interface" which is not an allowed Namespace name. Renamed to
SqlInterface

Moved the detect lang/etc function used in Form/Generate,
Template/SmartyExtend and Admin/Backend to Language/GetSettings.

Fixed some test class calls

www/lib/CoreLibs/ACL/Login.php

@@ -168,7 +168,7 @@ class Login
 	 * @param \CoreLibs\DB\IO              $db   Database connection class
 	 * @param \CoreLibs\Debug\Logging      $log  Logging class
 	 * @param \CoreLibs\Language\L10n|null $l10n l10n language class
-	 *                                     if null, auto set
+	 *                                                if null, auto set
 	 */
 	public function __construct(
 		\CoreLibs\DB\IO $db,