[Bro] Adding SSL certs to Bro 2.0

[Mathew Binkley]

I heard back from some of the guys at FNAL, and they pointed out the
FNAL CA cert is part of the IGTF distro:

  http://www.igtf.net

and 3 tarball of certs at:

   https://dist.eugridpma.info/distribution/igtf/current/accredited/

That covers most of the major scientific/research CA's I know of.
Adding those to Bro would complement the list of commercial CA's
extracted from Mozilla.


Mat