Instead of needlessly storing information in configuration section, pass it
via jinja2 parameter. This is safe, in case if extra_slave_instance_list
would contain value like ${section:option}.

Mainly to fix parallel build.

https://wiki.saucelabs.com/display/DOCS/Test+Configuration+Options#TestConfigurationOptions-MaximumTestDuration

There is a way to pass monitor port to each replicated frontend by using
frontend-config-N-monitor-httpd-port, thus there is no need to pass through
the default value, as it comes default on each replicated slave.

I noticed by accident that tests for `software/wendelin/software-dev.cfg` where failing because buildout was picking eggs:

```
Installing eggs.
While:
  Installing eggs.
  Getting distribution for 'scikit-learn'.
Error: Picked: scikit-learn = 0.19.2
Failed to run buildout profile in directory '/srv/slapgrid/slappart7/srv/testnode/acv/soft/78ae8a6d8b0639addb22de2c7c96af63'
```

Turned out it was a problem with usage of `zc.recipe.egg:develop`

There was also a problem which `${gcc-fortran:}` that does not exist anymore.

/reviewed-on nexedi/slapos!395

Turned out we are not ready to apply the part about storing wrappers in
${bin:directory} from "Firefox: install wrappers in
${buildout:bin-directory} and version up"

This commit is to be reverted once we update test nodes to 1.0.73 or
higher

Slapos compatible wrapper is no longer installed in `parts/firefox/firefox-slapos` , but directly as `firefox` in the `${buildout:bin-directory}` of the software. `geckodriver` is also in the same directory.

Firefox version up to 52.9.0esr

Geckodriver version up to 0.17.0


/reviewed-on nexedi/slapos!387

:develop is a bit special in that it does not install the egg, but just
tell buildout that this directory contain the egg, so that recipes that
will install this egg later will pick the develop-eggs.

  Allow the KVM software release request a disk via plugin,
  if the plugin is enabled the chown will be set to give the disk to the partition.

Not released yet functionality for regular expression cookie rewriting
is available: https://github.com/mholt/caddy/pull/2144

Add plugin assertions in TestSlave.test_master_partition_state and drop
check-free-disk-space from promise directory.

/reviewed-on nexedi/slapos!380

Introduce a simple tool to format JSON for software instance definitions.
This tool is inspired by `python -m json.tool`, but has the following differences:
 * keep the order of keys instead of sorting alphabetically (because we sometimes put the most important options at the top)
 * indent with 2 spaces

Run the tool on all the repository and commit the changes, with this command: 
```
for x in $(find . -name '*.json') ; do  echo $x; ./format-json $x $x; done
```

/reviewed-on nexedi/slapos!392

As check-free-disk-space promise is implemented in plugin directory, add it
to list of assertions and drop it from promise list assertions.

Also already existing monitoring plugins are asserted.

Before we move this code to a more suitable place, start by agreeing with small differences in the implementation.

This takes all the nice changes from caddy-frontend/tests/ but not what was specific to caddy or to testing slave instances.

/reviewed-on nexedi/slapos!389

This release should be now stable enough for release

/reviewed-on nexedi/slapos!391

In preparation for moving this to a better place, use the same code in
all the places where this code was duplicated.

Reconcile all implementations, document a little bit more the methods
and the future plans.

It is combination of requestoptional and serialised.

In order to avoid needless inheritance create JSONCodec and use it, also
with renaming Serialised to RequestJSONEncoded.

Also provide a test asserting that important log is seen in case if no expected
return is set.

Add testfixtures module to catch logging.

Current ESR version

Keep version 51 for now

This reverts 8f35ea4d
It should no longer be needed because erp5.util should now have the fix
from
nexedi/erp5@97f3310e