moves python2 release to component/jupyter-py2 because it is required by ERP5
but not maintained anymore

moves to python 3 :
- test/test.py
- jupyter_notebook_config.py.jinja
- ERP5kernel.py

modifies custom.js to create a workaround for events issue
see (https://github.com/jupyter/notebook/issues/2499)

upgrades slapos.cookbook version to 1.0.171 to use zero_knowledge recipe
with python 3

adds jupyter partition check in software/erp5/test/test_erp5.py

To fix caucased failures:
  File "caucase/caucase/http.py", line 799, in main
    http_cas=http_cas,
  File "caucase/caucase/http.py", line 397, in getSSLContext
    http_cas.createCertificate(csr_id)
  File "caucase/caucase/ca.py", line 281, in createCertificate
    template_csr=template_csr,
  File "caucase/caucase/ca.py", line 328, in _createCertificate
    x509.SubjectKeyIdentifier,
  File "cryptography-2.3.1-py2.7-linux-x86_64.egg/cryptography/x509/extensions.py", line 189, in from_issuer_subject_key_identifier
    key_identifier=ski.value.digest,
AttributeError: 'SubjectKeyIdentifier' object has no attribute 'value'

In turn, this requires updating cryptography dependencies.
In turn, this requires updating requests as our old version is
incompatible with current idna version.
In turn, this requires updating requests dependencies.
And finally, this allows/requires updating some pins in SRs:
- software/jupyter: Version up certifi.
- stack/erp5: Un-pin chardet, as it is already pinned at stack/slapos level.

For some SR, it implies the following upgrades:
- decorator: 4.3.0
- gitdb2: 2.0.5
- smmap2: 2.0.5
- subprocess32: 3.5.3

- not all SR was using Cython 0.28.2
- with an upcoming upgrade of pycocotools, matplotlib>=2.1.0 will be required

this partially reverts ba52eead

Numpy version 1.16.4 was not compatible with scipy 0.19.0

Tests passing, merging right away.

/reviewed-on nexedi/slapos!586

 zc.buildout version up to 2.5.2+slapos012
 slapos.recipe.template version up to 4.3
 slapos.core version up to 1.4.4

numpy  >= 1.13.1 is required for numpy.core.multiarray

JupyterLab is provided side-by-side with Jupyter Classic interface with same process.

Published URL changed:

 * jupyterlab-url provides IPv6 URL to JupterLab interface
 * jupyter-class-url provides IPv6 URL to the classic UI

Thanks to using only one process, the path in the URL differentiates the style of the interface.

Note: This MR replaces closed nexedi/slapos!207

/reviewed-on nexedi/slapos!218

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

/reviewed-on nexedi/slapos!197

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

IPYTHONDIR was usable for old versions of ipython, but since project was
renamed to Jupyter the environment variable is JUPYTER_CONFIG_DIR.

Ref:
http://jupyter.readthedocs.io/en/latest/projects/jupyter-directories.html#envvar-JUPYTER_CONFIG_DIR

/reviewed-on nexedi/slapos!188

@luke @Tyagov 

In Jupyter notebooks users could enter the url of their `Base_executeJupyter` function, but [it now gets filled in automatically](https://lab.nexedi.com/nexedi/slapos/blob/2f2a5ad0/software/ipython_notebook/template/ERP5kernel.py.jinja#L10). This makes the `%erp5_url` magic redundant which is why we can remove it. This commit also removes all mentions of `%erp5_url` in the kernel output and `custom.js`.

/reviewed-on nexedi/slapos!185

@Tyagov @luke 

This MR adds the following to all Jupyter notebooks:
 - A warning when a user inputs a reference that has already been used in one of his old Jupyter notebooks. 
 - Some extra information when entering magics such as the remaining required magics.
 - Entering the reference MUST now be the last magic entered(otherwise the reference check doesn't work).
 - A small addition to the message at the top of the notebook for the command ```%notebook_set_title```

Also, do note that the edited kernel uses files from [this commit](nexedi/erp5@4a3e5173) from my erp5 repo, so the changes there must be available for the kernel to work. [This merge request](nexedi/erp5!283) addresses those changes.

Sample screenshot:
![Screenshot](/uploads/a34e0b70b991302539c572ad4344ba56/Screenshot.png)


/reviewed-on nexedi/slapos!177

@Tyagov  @kirr 

/reviewed-on nexedi/slapos!171

Tests do pass in https://nexedi.erp5.net/test_result_module/20170530-4EB92D8F/view

/reviewed-on nexedi/slapos!168

Added password generation and monitoring to jupyter instances. Todo: Password editing at the monitor.

A redo of [this](nexedi/slapos!148) merge request. I messed up with some merge conflicts on the old one and thought it would be faster to make a new one...

@alain.takoudjou  @Tyagov 

/reviewed-on nexedi/slapos!156

fixup! software/ipython_notebook: Update ERP5kernel.py.jinja, send store_history parameter to ERP5 so that we can use this flag to decide whether to add a data notebook line or not.

use slapos.recipe.build:download and slapos.recipe.build:download-unpacked instead of hexagonit.recipe.download.