projects.

The configure option requesting AFS kaserver support (and thus
building kasetkey) is now --with-kaserver instead of --with-afs.

If KRB5_CONFIG was explicitly set in the environment, don't use a
different krb5-config based on --with-krb4 or --with-krb5.  If
krb5-config isn't executable, don't use it.  This allows one to
force library probing by setting KRB5_CONFIG to point to a
nonexistent file.

Sanity-check the results of krb5-config before proceeding and error
out in configure if they don't work.

Stop setting Stanford-specific compile-time defaults for the wallet
server and port.