component/percona-toolkit: upgrade to 2.2.17 to fix bugs caused possibly due to updating perl to 5.26

We recently moved to perl 5.26 from 5.20 which breaks the pt-digest and possibly other percona tools.
The fix for percona tools was added in release 2.2.17 onwards and the patch for the same can be found
here: https://github.com/percona/percona-toolkit/pull/73

The caucase parameter 'auto-sign-csr' used to say if the first csr should be signed
was changed to 'auto-sign-csr-amount' to let specify how many csr can be signed without
human intervention.
This parameter will be set to 2 in erp5 software release, so that caucase http server and
apache server cas request thier certificate automatically.

/reviewed-on nexedi/slapos!203

whenever the zope instances have the same title (example all zope have 'Zope monitor' as title) the request to frontends consider it as the same request and gives same frontend to each of them.

/reviewed-on !202

http://mailman.nginx.org/pipermail/nginx-announce/2017/000200.html

See the comments at [this MR](nexedi/slapos!193).

/reviewed-on nexedi/slapos!200

 The principle of deployment on slapos is once the instance is read to use the
 all the promises must work and buildout would stop to run for a while. This
 Promise is been disable because it assumes the user must use the instance first
 them the promise will be green, which can cause endless failure.

 This fail until user do something makes tests and resilience fail, as there is
 no automation to emulate a user take some action.

 This problem MUST be reimplemented on the current way, and not assume user will
 do any action. Others promises can be added into monitor (but not this one like this).

  extra-eggs conflicts with monitor setup.

Added a buildout.hash.cfg for generating automatic md5sums.

/reviewed-on nexedi/slapos!197

Allows requesting a caucase partition and reusing an existing caucase instance.
For client-certificate-based authentication, client must be able to access backend
directly (frontend is not possible).

  This block could be generalized a bit more but it will be unlikely to have computers with more them 1000 partitions.

* component/automake: version up 1.15.1 for perl 5.26.
* component/perl-Encode-HanExtra: fix for perl 5.26.0 that no longer contains . in @INC.
* component/perl-XML-NamespaceSupport: fix for perl 5.26.0 that no longer contains . in @INC.
* component/intltool: version up 0.51.0 and add a patch for perl 5.26.
* component/perl-CGI: added for w3-validator because Perl 5.26 no longer includes it.
* component/perl-URI: version up 1.71.

See !193's comments.

/reviewed-on nexedi/slapos!194

@luke @Tyagov 

When SlapOS launches services they don't have their locale set. This was causing problems with unicode characters in Jupyter notebook names. For example, calling the notebook "Ł" crashes Jupyter's kernel. Hardcoding the UTF-8 locale to the ipython_notebook script fixes that but we should look into making a generic fix for any other services that might have this issue in the future.

/reviewed-on nexedi/slapos!193