Issue #675 Modification of data structure outside of the transaction when constraint...

Issue #675 Modification of data structure outside of the transaction when constraint between segmnet and construction element

1 problem: operation has the previous list of preselected objects, it should be cleared after activateByPreselection is done.
2 problem: second parallel constraint operation has not empty first value. the reason is that the selection is cleared only in Viewer, but not in the OB.