r20639: Commit part 1 of 2.

r20639: Commit part 1 of 2.

This patch updates our build system and glue to support a new snapshot
of lorikeet-heimdal.

We now procude a [SUBSYTEM] in the ans1_deps.pl script, and can depend
on that in the heimdal_build/config.mk.  This is much easier than
listing every generated .o file individually.

This required some small changes to the build system, due to the way
the parent directory was handled for the output of scripts.  I've also
cleaned up et_deps.pl to handle cleaning up it's generated files on
clean.

The PAC glue in Heimdal has changed significantly: we no longer have a
custom hack in the KDC, instead we have the windc plugin interface.
As such, pac-glue.c is much smaller.  In the future, when I'm
confident of the new code, we will also be able to 'downsize'
auth/kerberos/kerberos_pac.c.

(I'll include the updated copy of heimdal in the next chekin, to make
it clearer what's changed in Samba4 itself).

Andrew Bartlett
(This used to be commit 75fddbbc0811010a28ca5bb597b573b3f10ef6d6)