[security] Avoid full path disclosure from some libraries script, see

PMASA-2013-12

Move the PHPMYADMIN constant definition earlier

libraries/Error.class.php

@@ -6,6 +6,10 @@
  * @package PhpMyAdmin
  */
 
+if (! defined('PHPMYADMIN')) {
+    exit;
+}
+
 /**
  * base class
  */

libraries/Error_Handler.class.php

@@ -6,6 +6,10 @@
  * @package PhpMyAdmin
  */
 
+if (! defined('PHPMYADMIN')) {
+    exit;
+}
+
 /**
  *
  */

libraries/common.inc.php

@@ -46,6 +46,11 @@ if (!defined('E_DEPRECATED')) {
     define('E_DEPRECATED', 8192);
 }
 
+/**
+ * for verification in all procedural scripts under libraries
+ */
+define('PHPMYADMIN', true);
+
 /**
  * the error handler
  */
@@ -79,11 +84,6 @@ if (version_compare(phpversion(), '5.4', 'lt')) {
     @ini_set('magic_quotes_runtime', false);
 }
 
-/**
- * for verification in all procedural scripts under libraries
- */
-define('PHPMYADMIN', true);
-
 /**
  * core functions
  */