- drop unnecessary Foam::Swap specializations when MoveConstructible
  and MoveAssignable already apply. The explicit redirect to swap
  member functions was needed before proper move semantics where
  added.

  Removed specializations: autoPtr, refPtr, tmp, UList.
  Retained specialization: DynamicList, FixedList.

     Special handling for DynamicList is only to accommodate dissimilar
     sizing template parameters (which probably doesn't occur in
     practice).
     Special handling for FixedList to apply element-wise swapping.

- use std::swap for primitives. No need to mask with Foam::Swap wrapper