r13206: This patch finally re-adds a -k option that works reasonably.

r13206: This patch finally re-adds a -k option that works reasonably.

From here we can add tests to Samba for kerberos, forcing it on and
off.  In the process, I also remove the dependency of credentials on
GENSEC.

This also picks up on the idea of bringing 'set_boolean' into general
code from jpeach's cifsdd patch.

Andrew Bartlett
(This used to be commit 1ac7976ea6e3ad6184c911de5df624c44e7c5228)