sl/symdiscover: export the digShapePropsCandidates() function
sl/cont_shape: traverse heap for entry candidates
sl/cont_shape: implement AparentShapeDetector::isFreeEnt()
sl/cont_shape: implement AparentShapeDetector::probeEntry()
sl/shape: provide the objSetByShape() converter
sl/symplot: allow to highlight clusters by IDs