[krbdev.mit.edu #7127] Can't change password without default_realm

[Greg Hudson via RT]

Also mentioned by Stef Walter on krbdev:

http://mailman.mit.edu/pipermail/krbdev/2012-April/010790.html

I'm evaluating which solution comes out to be more elegant (adding an 
ignore-realm flag to krb5_parse_name_flags or preprocessing the 
in_tkt_service string).