[rql2sql] closes #1892473: enhance handling of optional inlined relation
* some outer join aren't supported while they could
* consider newly available 'optcomparisons' st information on variables (rql 0.30)
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s precreate script, executed at instance creation time or when
the cube is added to an existing instance, before the schema is serialized.
This is typically to create groups referenced by the cube'schema.
"""