Running "tunctl" will result in creation of a tap interface. In order to avoid
it call it with some "-d" parameter which will make it exit fast.

Facebook and Google implementation depends on this modules.

The workflow history is long and results in memory leaks while traversal,
which consumes (forever) lot of memory  on activity nodes.

It makes delivery non writable, so just do it after all operations.

It reverted part of 721f4f27.

Squashed commit of the following:

commit a9aa690c5b74de55fed2499cbe6a2a205fbc2550
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Fri Aug 17 10:18:14 2012 +0200

    Introduce use of logger

commit a36d37f766062eb5faed1e179d64a6c6a2bc2e50
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 16 19:05:09 2012 +0200

    update copyright from 2010 to 2012

commit 167c2a83d45a5e1ca88dab806a5612e981aaf6a9
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 16 19:02:56 2012 +0200

    Add dry run control in saving old configuration

commit 80eecf880c214c96d780547e95c447d794a87c0e
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 16 19:00:35 2012 +0200

    Clean code

commit 359cf29263e72f2070659d7fdc1ba227dff85426
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 16 18:51:43 2012 +0200

    Moved comments to docs

commit 84077e2a926b7d8fdf2495001df9378a301b5bbd
Merge: 42f2b2d 8d7ba61
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 16 18:46:52 2012 +0200

    Merge remote-tracking branch 'origin/register' into register

commit 42f2b2dae626dfa7ef54f2df97e21d089e5890d7
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 16 18:46:31 2012 +0200

    Moved register.py to register/

commit 8d7ba617c3d0697683eff48aee8401067d23c413
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 16 10:48:48 2012 +0200

    Display error if wrong usage

commit 927d395f2f3e1f01085c38ea681f16034182e2bd
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Tue Aug 14 14:57:33 2012 +0200

    Added created_tap = false in slapos.cfg

commit 49669afd0514f01b4720f94137c1f76cc47b4904
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Tue Aug 14 12:05:07 2012 +0200

    If a slapos.old file is find, backup will be made in slapos.old.i
    Where i is the lower integer available starting at 1

commit 430406f39753af3f2de26e5a631350c5fb997a3a
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Tue Aug 14 11:04:11 2012 +0200

    Can pass login and password in command line argument

commit 50b19497981d274f327fbe44c619a221539697aa
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 9 11:49:29 2012 +0200

    Solved bug in writting interface in slapos.cfg

commit 27fe79c859a65095493303da7f81ace0c3643641
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 9 10:51:10 2012 +0200

    Added option to modify master webservice url for computer registration

commit 9ed75848324789bb01404592780ba7cd2ab65f3c
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 9 10:17:28 2012 +0200

    Removed useless recursive include in MANIFEST.in

commit 6b2d90c0b8149872b56dc9b565cb4800c3183594
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 9 10:08:31 2012 +0200

    removed useless parameters in Option function call

commit 34083f2351570a1413bffb18db05bd17a6a8a18c
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 9 10:06:07 2012 +0200

    removed useless '/'.join in os.path.join

commit 8408a213e655cc9030493d8a4695a4e4c0380c30
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Thu Aug 9 09:53:07 2012 +0200

    Withdraw unused module from code

commit 2805cf2a9927e0b09a60984f7255423602e37e31
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Wed Aug 8 16:17:31 2012 +0200

    Fixed forgotten code

commit 35e0b0ba9c6a7a9782a895b7ff74ab1294d1cad2
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Wed Aug 8 15:53:50 2012 +0200

    Added slapos entry point, just giving acces to register script now

commit d2456a5a5f9135176498ac40088850627e21f88c
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Wed Aug 8 11:46:34 2012 +0200

    Register function is now made to run in command line
    ipv6 interface option added

commit 71bc5c9edae00502cf09abaac4a4d70be96d4a9a
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Tue Aug 7 17:40:56 2012 +0200

    Added creation partition_pki repertory

commit e80fede661858f98d0508bf61c4489b2e174882e
Author: Cédric Le Ninivin <cedric.leninivin@tiolive.com>
Date:   Tue Aug 7 17:01:23 2012 +0200

    Introducing independant register function that saves configuration in /etc/opt/slapos/slapos.cfg

This will allow to be sure globally, that production code is generating
correct documents.