Log Message:
Let the user enable/disable Kerberos 4 and 5 support through the new krb4
and krb5 options.  These are disabled by default, so bump PKGREVISION to 4
because the package was previously finding and using both libraries.

Also forbid the usage of krb[45] options together with ssl.  This fixes a
crash when using SSL, because the Mozilla NSS libraries and libcrypto (used
by Kerberos) have functions with the same name.  I don't know why this
worked for me in the first place, but it doesn't any more.