rm veto False

introduced in b1ceb9681f2fe6e42a9fa1f405cea869d6b8a1bc
update abstract test after fix to is_adjacent

was applied in d3102d4ffc2fe4ea70de4441e963e51884d29a43
update prop2part test to renamed method
make bounding_box a property
make overlap=False default in is_adjacent

because it is fragile, consistently missing adjacency relations.

Add an abstract unit test to check for correct adjacency
plot progress ratio
__init__ super from PropPreservingPartition