Handle Event "Could not find valid value for id" when HTTP Referer exists

[mlutfy]

I suspect these are caused by QuickForm session errors. However, they can be difficult to reproduce in 4.7 (they were pretty common in 4.6 because of the cleanup jobs).

When this error happens, we should redirect back to the event page, with a session timeout message.

Example:

HTTP_REFERER:       https://civicrm.org/civicrm/event/register?id=1155&reset=1

***BACKTRACE***
#0 /var/aegir/platforms/civicrm-org/sites/civicrm.org/civiext/ca.bidon.reporterror/reporterror.php(251): reporterror_civicrm_generatereport("CiviCRM", (Array:2), NULL, (Array:0))
#1 /var/aegir/platforms/civicrm-org/sites/all/modules/civicrm/CRM/Core/Error.php(365): reporterror_civicrm_handler((Array:2))
#2 /var/aegir/platforms/civicrm-org/sites/all/modules/civicrm/CRM/Utils/Request.php(120): CRM_Core_Error::fatal("Could not find valid value for id")
#3 /var/aegir/platforms/civicrm-org/sites/all/modules/civicrm/CRM/Event/StateMachine/Registration.php(52): CRM_Utils_Request::retrieve("id", "Positive", Object(CRM_Event_Controller_Registration), TRUE)
#4 /var/aegir/platforms/civicrm-org/sites/all/modules/civicrm/CRM/Event/Controller/Registration.php(47): CRM_Event_StateMachine_Registration->__construct(Object(CRM_Event_Controller_Registration), TRUE)
#5 /var/aegir/platforms/civicrm-org/sites/all/modules/civicrm/CRM/Core/Invoke.php(304): CRM_Event_Controller_Registration->__construct("Event Registration", TRUE, "null", NULL, "false")