Add erp5_scalability_data bt5

Contain objects and scripts needed to perform scalability tests.
erp5_promise: add script wich launch Fix Configuration Consitency

This script in order to be able to fix the site consistency via an url.
This script is present in erp5_promise because erp5_promise is one
of the bt5 installed by default. Fixing site consistency permits
to install others bt5 as erp5_configurator_standard.
This script is called externally via his url during the bootstrap
of scalability tests.
benchmark: modify and add new benchmark

These benchmarks are used during scalability tests.
A file which contains list of scalability users is also added.
performance_tester: add command line options to use different paths.

Add option to specify several path where to find users file(s),
and benchmark suite file(s).
performance_tester: remove duretion option (to rebase with previous commit)
browser: change xpath expression to take into account <tbody> tag.
performance_tester: to rebase with performance tester new option
erp5_configurator_standard: add business_configuration_module object.

This new object has a bad id, we should change it. Also, may not be
in the good place in erp5_configurator_standard and should be
moved in another bt5.
The reason of his place in erp5_configurator_standard, is that
erp5_configurator_standard is automatically installed when
fix site consistency is done, thereby it install this preconfigured
object to. If this object is moved, the bt5 which will contains it
must be added to the list of bt5 to install when doing check site
consistency.
testnode: Modify testnode structure to include scalability tests.

Testnode code has been splitted. Runner class has been created for
each test types (unit and scalability).
Communication with SlapOS and ERP5 Master has been added.
Add scalability test suite runner.

This runner is used by scalability test, it communicates
with ERP5 Master and launch test suite (using performance_tester).