Fix permission issue with new events created by users with only 'access CiviEvent' permission

There are use cases for allowing users with only 'access CiviEvent' permission to create new events. However, a problem was introduced when CRM_Core_Page_AJAX_Location::getLocBlock was changed to require 'access CiviCRM'. This issue fixes that problem.

NOTE: 'access CiviEvent' should never be given to anonymous users AND is not needed to allow users to view event info or register for events. In 4.5 we will add a 'configuration warning' for sites that have granted access CiviEvent (or access $component) permission to the anonymous role.