Add krb5_free_context stub to rfc3961

Reviewed-on: http://gerrit.openafs.org/10048
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Simon Wilkinson <simonxwilkinson@gmail.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit f388f0a85a53a42c3e8f4075d4228b64d0fc558c)

Change-Id: Id1fd9ad4b226c90dddee779b1d31be353e49ec9e
Reviewed-on: http://gerrit.openafs.org/10061
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Disable some heimdal bits

For the rfc3961 library, we don't want linker exposure to an
entropy-gathering daemon, and we don't want to be leaving entropy
seed files around in user homedirs.

Reviewed-on: http://gerrit.openafs.org/10049
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Simon Wilkinson <simonxwilkinson@gmail.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit ef860802add62076ca6097808458706d3db8d0da)

Change-Id: I0404b4871f86b324782bd8f42f38ae5fb125252e
Reviewed-on: http://gerrit.openafs.org/10062
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>