Added text about lowest level differences with make_perf_cert.  Added comments about using the ANYSKI flag to prevent checking of the SKI of embedded end-entity certs.
Added text about lowest level differences with make_perf_cert.  Added comments about using the ANYSKI flag to prevent checking of the SKI of embedded end-entity certs.


rhansen/rpstir,rhansen/rpstir,rhansen/rpstir,rhansen/rpstir,rhansen/rpstir