[krbdev.mit.edu #3361] default profile path

[Ken Raeburn via RT]

On most UNIX platforms, the default profile path (DEFAULT_PROFILE_PATH
in osconf.h) has the system-wide version (/etc/krb5.conf) ahead of the
installation-specific one (@SYSCONFDIR/krb5.conf).  Since we don't
install this config file, any krb5.conf found in $sysconfdir is going
to have to have been supplied by the sysadmin, or whoever installed
the executables.  So, shouldn't we check for the installation-specific
one first, ahead of the one shared by all installations?

Granted, it'll be a wee bit slower in the normal case since we'd stat
the non-existent file before seeing that /etc/krb5.conf hasn't changed
since the last time we looked, but I don't think it'd be a big deal.

Ken