Big Refactoring (BR) of the test execution model Get rid of narval preprocessors in favor of Recipes - Each preprocessing recipe must be run from the "main" recipe (thus we add a ATest.exec_recipe() method that can be called from Recipe execution). - We add a (Repository, checkout_recipe, Recipe) relation, which is the Recipe that tells how to retrieve the code for a given Repository - Also add a (ProjectEnvironment, setup_recipe, Recip) dedicated to perform the installation for a project (compile and install) - Add implementations for these recipes for Python project - Rewrite the quick recipe using this new model

# normally executed with following builtin variables:
# :source_url:
# :rev:
# :dstdir:

import os
import hglib

os.environ['HGRCPATH'] = os.devnull

configs = [('ui.username', 'narval'),
           ('phases.publish', 'False'),
           ]

if not os.path.exists(dst_dir):
    os.makedirs(dst_dir)
hglib.clone(source_url, dst_dir, updaterev=rev)