Add knc_get_service()

And make knc_get_{client, service}() work symmetrically, calling
gss_inquire_context() as needed (and always on the service side), but
only once per-context.
Formatting.
Minor update to liknc.3 regarding naming
Add knc_free_deleg_cred()

And note that knc_set_cred() can be used to release credentials set
earlier.  This is useful when one wants to keep a security context but
drop privs and access to privileged credentials.
knc(1) should export name and mechanism OID
Use gss_oid_to_str()
Only set KNC_CREDS if mech is krb5
void funcs should not return values
fix indentation and unexpand tabs
fix long lines
fix comments
Fix ownership of gss values issues

Conflicts:
	lib/libknc.c

Fixed conflict.  Original patch from nico.
libknc.h needs to include sys/uio.h to get iovec
Formatting.
We should do something reasonable even if we can't find gss_oid_to_str().

So, we set it to the empty string or "krb5" if it's Kerberos.
s/knc_authenticated/knc_is_authenticated/.