CRM-15629: Add wpLoadPhp to core settings file

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* CRM-15629: Paypal IPN not working on Wordpress the first time
  https://issues.civicrm.org/jira/browse/CRM-15629

Author: kcristiano

settings/Core.setting.php

@@ -734,4 +734,20 @@
     'description' => 'When enabled, "empowered by CiviCRM" is displayed at the bottom of public forms.',
     'help_text' => NULL,
   ),
+  'wpLoadPhp' => array(
+    'group_name' => 'CiviCRM Preferences',
+    'group' => 'core',
+    'name' => 'wpLoadPhp',
+    'type' => 'String',
+    'html_type' => 'text',
+    'quick_form_type' => 'Element',
+    'prefetch' => 1,  // prefetch causes it to be cached in config settings. Usually this is a transitional setting. Some things like urls are permanent. Remove this comment if you have assessed & it should be permanent
+    'default' => '',
+    'add' => '4.6',
+    'title' => 'WordPress Path to wp-load.php',
+    'is_domain' => 1,
+    'is_contact' => 0,
+    'description' => 'CiviCRM will use this setting as path to bootstrap WP.',
+    'help_text' => NULL,
+  ),
 );