Improvements to the performance of SCF.member and SCF.not_member

1. Reduce the number of ESat.Undefined cases for PropIntMemberSet.isEntailed.
2. PropNotMemberSetInt's constructor specifies to react on fine events yet it did not implement an incremental propagation.
3. Set to passive when PropNotMemberSetInt or PropNotMemberIntSet can guarantee that the domain of the integer variable does not overlap with the envelope of the set variable.
Merge pull request #252 from JLiangWaterloo/set-membership-perf

Improvements to the performance of SCF.member and SCF.not_member