Add "Get1DEnumerable",  "GetAll1DEnumerables" method  and thier test "GetAll1DEnumerables_Test".
Add check process in ctor and test method "NormalCtor_FailTest".
Add ctor with 2D rectangular array, test method "CtorWith2DRectangularArray_Test" and "CtorWith2DRectangularArray_ArgumentNull_FailTest".
Add ctor with jugged array, test method "CtorWithJuggedArray_Test", "CtorWith2DJuggedArray_ArgumentNull_FailTest" and "CtorWith2DJuggedArray_ArgumentUnflatted_FailTest".
Rename some test methods.