Basic pluto with IKEv2 using PSK on the initiator (west), and on the responder.

This test adds a bogus ISAKMP RESERVED flag to the payload on the responder

RFC 5996 Section 2.5:

   Also, for forward compatibility, all fields marked RESERVED MUST be
   set to zero by an implementation running version 2.0, and their
   content MUST be ignored by an implementation running version 2.0
