succesful.
(get_new_cache): return better error codes and return earlier.
(get_cred_cache): only delete default_client if it's different from
client
(kadm5_c_init_with_context): return a more descriptive error.
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@5312 ec53bebd-3082-4978-b11e-865c3cabbd6b