Move internal declarations from k5-int.h to more localized headers
(like int-proto.h) where appropriate.  Rename many symbols whose
prototypes were moved to use the k5_ prefix instead of krb5int_.
Remove some unused declarations or move them to the single source file
they were needed in.  Remove krb5_creds_compare since it isn't used
any more.

If krb5_init_context fails, use a null context for getting the error
message, not a context we haven't yet initialized.  Observed by David
Benjamin <davidben@mit.edu> using clang.

Add a new pluggable interface for local authorization, and replace the
existing krb5_aname_to_localname and krb5_kuserok implementations with
implementations based on the pluggable interface.

ticket: 7583 (new)

lookup_etypes_for_keytab was not freeing the keytab entries it
iterated over.  Reported by nalin@redhat.com.

ticket: 7586
target_version: 1.11.2
tags: pullup

Rename krb5_free_ktypes to krb5_free_enctypes and add it to the public
API.

ticket: 7584

ticket: 7585

Prior to 1.11, it was possible to do SAM-2 preauth exchanges with
multiple hops by sending repeated preauth-required errors with
different challenges (which is not the way multi-hop exchanges are
described in RFC 6113, but it can still work).  This stopped working
when SAM-2 was converted to a built-in module.  Make it work again.

ticket: 7571 (new)
target_version: 1.11.1
tags: pullup

Result code 0 used to be converted properly by krb5_set_password,
though not krb5_change_password; this changed in 1.10 when
krb5int_setpw_result_code_string was folded into
krb5_chpw_result_code_string.  Restore the old behavior, and make it
apply to krb5_change_password as well, by making
krb5_chpw_result_code_string convert result code 0.

[ghudson@mit.edu: commit message]

ticket: 7569 (new)
target_version: 1.11.1
tags: pullup