symmetric relations: replace bogus rql2sql translation by a hook
The hook ensures X r Y => Y r X iff r is symmetric.
The rql-no-hook data importer receives a small amendment but note
that:
* there exist no test for it
* its actual semantics are undefined
Hence we cannot prove this hunk breaks nothing, because we cannot
prove anything.
Closes #3259713.
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from yams.buildobjs import RelationDefinition
class friend(RelationDefinition):
subject = ('CWUser', 'CWGroup')
object = ('CWUser', 'CWGroup')
symmetric = True