erp5/util/testnode: hosting subscription url was not updated once it was set. As a result, since testnode watched an old destroyed instance, the next test never started. Thus don't store hosting subscription url. It changes from time to time.

erp5.util.testbrowser: Refactor of openNoVisit() and {Image,Submit}Control for recent zope.testbrowser (followup of 5a0b3763).

Instead of sleeping, try using an API method until it stops raising
ConnectionError.

/reviewed-on nexedi/erp5!650

- hardcoded parameter removed
- minor changes in slapos master communicator

- allow slapos master communicator to supply software destruction
- runner reinstalls software on every commit (temporarily)
- refactor in software profile construction
- some try controls added

/reviewed-on nexedi/erp5!644

- before create a new instance checks if the current testsuite has an old one
- re-uses file-dictionary functions of frontend software checks
- minor fixes

/reviewed-on nexedi/erp5!615

By using `os.path.normpath` we also support paths with a trailing slash.

- requests to bootstrap and site availability urls using a script run with userhosts
- hardcoded parameters removed
- try-exception controls in communication with master
- general refactoring and cleanup

- test duration is get from testsuite definition
- refactoring and cleanup in runScalabilityTestSuite and benchmark
- request timeout in metric thread

/reviewed-on nexedi/erp5!607

- bug fixing while getting instance_guid
- minotr refactoring in request parameters

This should fix the problem that `Revision History` is unusable on test
results because tests have a different name when they have been running
on different paths

This will be used to run tests using interpreter with pre-installed
eggs, generated with zc.recipe.egg's interpreter

- testnode saves in its config the repositories paths
- minor refactoring and cleanup

/reviewed-on nexedi/erp5!606

- the commands to run the tests are launched using threads
- a thread is used to ask instance for metrics periodically
- refactoring for a more generic code
- refactoring in log handling
- old code related to created documents and create users removed
- new script parameters
- general refactoring and cleanup

- hardcoded software release url removed (http with password protection for now)
- scalability runner handles frontend request. It asks for a local master frontend apache software installation and instance request.
- testsuite brings the urls corresponding to instance, bootstrap, metrics collection.
- vinculation between scalability runner and runScalability script. Process manager is used to run the script as a command.
- scalability runner manages the test result cases and loops among different testsuite configurations.
- userhosts software is used to run the command for the runScalability script, to solve DNS.
- refactoring according to last changes in TaskDistribution
- general refactoring and cleanup

- communicator considers requests of master frontend and instance destruction.
- communicator retrieves frontend related information from instances.
- minor refactoring and code cleanup.

- TestThread runs a target command using a testnode-process-manager
- TestMetricThread makes a get request to a target url periodically and collects the responses

The /bin/ folder of all extra SR provided by the testnode are added to PATH.
SR must fixed either by moving executables or adding symlinks.

The testnode will stop looking at the parameter list of runTestSuite,
and --firefox_bin/--xvfb_bin are deprecated.

This is part of defining a generic and unique API between the testnode and
the tested software.

Conflicts:
	erp5/util/testnode/ProcessManager.py

A lot was found with pylint.

Removed code from not implemented and not needed compatibility layer.

/reviewed-on nexedi/erp5!525