Djsopnet: fix SolutionGuarantor testing script

Fix the script to correctly iterate through all cores in the stack.
Djsopnet: model cliques of slice conflicts

To be able to reconstruct maximal cliques in sopnet for which
explanation can be forced, store cliques of conflict edges between
slices. Rename SliceConflictSet to SliceConflict to avoid equivocation
with ConflictSets in sopnet for this reason. Update views accordingly.
Djsopnet: fix integrity check for multiple cores
Djsopnet: speed up database clearing
Djsopnet: force explanation in test script (minor)
Djsopnet: update use of section to reflect sopnet

Sopnet now stores sections as the supremum rather than infimum, so
update uses accordingly.
Djsopnet: fix rule for updating solution precedence

The precedence upsert rule was attempting to update all cores, not just
the core for the original insert.
Djsopnet: update segment section field name

Update the name of Segment's section field to section_sup to reflect its
change in meaning from section infimum to section supremum.
Djsopnet: add integrity check for segment ends

Check that all slices have exactly two ends. This is useful for checking
integrity at volume boundaries.