talloc: Decouple the dual use of chunk->pool

If we want nested pools, we will have pools that are pool members. So
we will have to have a separate "next object" pointer  for pools. As
we have struct talloc_pool_chunk now, this additional pointer does not
affect normal talloc objects.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
talloc: Introduce __talloc_with_prefix

This will allow to exchange the extra talloc pool header with the
talloc_chunk structure

Signed-off-by: Volker Lendecke <vl@samba.org>
Signed-off-by: Jeremy Allison <jra@samba.org>
talloc: Put pool-specific data before the chunk

This is a preparation to make talloc pool real objects themselves.

Signed-off-by: Volker Lendecke <vl@samba.org>
Signed-off-by: Jeremy Allison <jra@samba.org>
talloc: Add a separate pool size

This is necessary to allow talloc pools to be objects on their own. It
is an incompatible change in the sense that talloc_get_size(pool) now
returns 0 instead of the pool size. When the talloc_pooled_object()
call is added, this will start to make sense again.

Maybe we should add a talloc_pool_size call? Or is that overkill?

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
talloc: Allow nested pools.

Signed-off-by: Volker Lendecke <vl@samba.org>
Signed-off-by: Jeremy Allison <jra@samba.org>
talloc: Add talloc_pooled_object

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
talloc: Test the pooled object

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
smbd: Use talloc_pooled_object in cp_smb_filename

Requires new talloc

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
tevent: Use talloc_pooled_object for tevent_req_create

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Sun Sep  8 13:39:25 CEST 2013 on sn-devel-104