be linked in when testing -lreadline usability so that test fails on
Solaris - so pass that lib into configure at the start via the environment.
Also allow optional use of db4 rather that db.
Kerberos implementation packages to decide whether to prefix certain
commands with a "k" to differentiate it from system tools with similar
names. KERBEROS_PREFIX_CMDS defaults to "no".
Heimdal is a free implementation of Kerberos 5.
Kerberos is a system for authenticating users and services on a network.
It is built upon the assumption that the network is "unsafe". Kerberos
is a trusted third-party service. That means that there is a third
party (the Kerberos server) that is trusted by all the entities on the
network (users and services, usually called "principals"). All
principals share a secret password (or key) with the Kerberos server and
this enables principals to verify that the messages from the Kerberos
server are authentic. Thus trusting the Kerberos server, users and
services can authenticate each other.