WIP: Caucase

Here is my work (still in progress) at integrating latest caucase into erp5 slaposification.

As preparatory work, to be reviewed by at least @seb, I stop using erp5.test recipe and instead build the wrappers directly from buildout configuration. This removes a lot of code and should make it much easier in the future to make runUnitTest/runTestSuite usage evolve.

Please comment on:

• Whether the 2 cloudoo backward-compatibility parameters are still needed (/cc @tc )
• Some code in ERP5 is relying on OPENSSL_BINARY environment variable for dubious needs (as acknowledged in a comment in that file). Is this still used ? If so, cleaner way needs to be found.

And the main work: actually moving all slaposification involving caucase to the latest release, simplifying it significantly in the process. I am still waiting for updated builds to finish locally. Here I have no specific desired review points, please review as much as possible.

/cc @alain.takoudjou @rafael