func (ll *LogList) Compatible(cert *x509.Certificate, certRoot *x509.Certificate, roots LogRoots) LogList {
	active := ll.TemporallyCompatible(cert)
	return active.RootCompatible(certRoot, roots)
}
Compatible creates a new LogList containing only Logs matching the temporal,
root-acceptance and Log-status conditions.
package loglist2
import (
	"github.com/golang/glog"
	"github.com/google/certificate-transparency-go/trillian/ctfe"
	"github.com/google/certificate-transparency-go/x509"
)
type LogRoots map[string]*ctfe.PEMCertPool