Provide a "post buildout steps" for functional testing

[Georges Racinet]

See https://pypi.python.org/pypi/anybox.buildbot.openerp#custom-builds for explanations about "post buildout steps"
This will be used for any testing that requires the server to actually run normally. These include:

- any functional testing with tools such as funkload or Selenium
- Javascript unit tests (AFAIK it's required to have a running server, among other things)

The common pattern to implement will be :
- start OpenERP server, listening on an available port
- launch commands specified from the MANIFEST configuration file.
- stop OpenERP server

[Georges Racinet (gracinet)]

Just pushed working implementation, for debian-based buildslaves only (uses /sbin/start-stop-daemon).
Use a capability and build-requires if you need to restrict to them.

For more universality, we might require the buildouts to have a supervisor dedicated part and use it to control openerp process, but I did not want to take that road right away

[Georges Racinet (gracinet)]

Showcasing with funkload, which is actually continuous integration for examples in both anybox.funkload.openerp and anybox.buildbot.openerp:

http://buildbot.anybox.fr/builders/funkload-6.1-postgresql-9.2

[Georges Racinet (gracinet)]

Released with 0.9