Make Boundary2D Generic for succ,pred and head

  - to keep Segment2D not Generical, extact a GenericSegment2D from segment2D
  - also trivially modify SupportDomainSeacherFactoryTest( .head to .getHead())
rename GenericSegment.bisection() to bisectionAndReturnNewSuccessor()

  - modify Polygon2D accordingly
Add adaptive package, AdaptiveCell, AdaptiveCellEdge and QuadrangleAdaptiveCell

  - haven't test