This change updates ipsec-tools to 0.8.0. However, a quick test reveals
a regression in IPSec PSK sessions. The server rejects the first packet
of phase 2 negotiation with INVALID-ID-INFORMATION error. After testing
files one by one, it turns out that using the old ipsec_doi.c fixes the
problem. Then the next error shows that identity check is failed. This
can be fixed by marking few lines in isakmp_quick.c just like 0.7.3.

This change adds ipsec_doi-0.7.3.c as a temporary fix. I will come back
and see if I can find the real problem. IPSec RSA sessions will be
covered in the next change.

Change-Id: I48f0026c3be07f506b3901b59202081bf88f41c9