Add "revoke" option, to revoke user's SSL certificates.
Add "revoke" option, to revoke user's SSL certificates.

Doing this:

	boss> wap tbacct revoke stoller

Will revoke all of the certs, and if PROTOGENI is enabled,
generate a new CRL and push that CRL to the Clearinghouse.

nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome