Unenrollment means that the host keytab is disabled on the server making
it possible to re-install on the client. This host principal is how we
distinguish an enrolled vs an unenrolled client machine on the server.
I added a --unroll option to ipa-join that binds using the host credentials
and disables its own keytab.
I fixed a couple of other unrelated problems in ipa-join at the same time.
I also documented all the possible return values of ipa-getkeytab and
ipa-join. There is so much overlap because ipa-join calls ipa-getkeytab
and it returns whatever value ipa-getkeytab returned on failure.
ticket 242
6de0834fca