Fix error message quotations in install_kdc.rst

Some error messages that kprop could print were quoted incorrectly in
install_kdc.rst.

Also fix minor typos.

ticket: 7785 (new)
target_version: 1.12
tags: pullup
Fix S4U2Self against non-FAST KDCs

When we added FAST TGS support in 1.11, we broke S4U2Self against KDCs
which don't support FAST, because the S4U2Self padata is only present
within the FAST request.  For now, duplicate that padata in the outer
request so that both FAST and non-FAST KDCs can see it.

ticket: 7791
target_version: 1.11.5
tags: pullup
Avoid malloc(0) in SPNEGO get_input_token

If we read a zero-length token in spnego_mech.c's get_input_token(),
set the value pointer to NULL instead of calling malloc(0).

ticket: 7794 (new)
Modernize sn2princ.c

Refactor and edit sn2princ.c to match current coding style.  No
behavior changes, except to be less chatty in trace logs.
Allow ":port" suffixes in sn2princ hostnames

MSSQLSvc principal names can contain a ":port" or ":instance" trailer
on the hostname part.  If we see that in the hostname argument of
krb5_sname_to_principal(), remove it before canonicalizing the
hostname and put it back on afterwards.

ticket: 7795 (new)
Add tests for krb5_sname_to_principal