remove #filterNotHavingValue(zero)
Introduce SMGHasValueEdgeSet#getNonZeroEdges()
Instead of SMGEdgeHasValueFilter#filterNotHavingValue() which is used only with zero, introduce SMGHasValueEdgeSet#getNonZeroEdges.
Add test to show the behavior is expected, remove old tests. Remove SMGEdgeHasValueFilter#value field.
Edited by Петров Олег Максимович