Ticket History #6586: libkrb5 support for non-blocking AS requests

Merge Luke's iakerb-libkrb5-as-only branch into trunk with several bug
fixes. Adds support for the krb5_init_creds APIs (same as Heimdal's)
which allow AS requests to be performed via a different transport than
the blocking send_to_kdc.


https://github.com/krb5/krb5/commit/dc3ba26a2c9acde7ca4ed9260fdc01997511e478
Commit By: ghudson
Revision: 23358
Changed Files:
U trunk/src/include/krb5/krb5.hin
U trunk/src/lib/krb5/krb/fast.c
U trunk/src/lib/krb5/krb/gc_via_tkt.c
U trunk/src/lib/krb5/krb/get_in_tkt.c
U trunk/src/lib/krb5/krb/gic_keytab.c
U trunk/src/lib/krb5/krb/gic_pwd.c
A trunk/src/lib/krb5/krb/init_creds_ctx.h
U trunk/src/lib/krb5/krb/int-proto.h
U trunk/src/lib/krb5/krb/mk_req_ext.c
U trunk/src/lib/krb5/krb/send_tgs.c
U trunk/src/lib/krb5/libkrb5.exports