- SLOT1BINFULL() macro: changed this to check for __rop__ overriding
  __op__, like binary_op1() in abstract.c -- the latter only calls the
  slot function once if both types use the same slot function, so the
  slot function must make both calls -- which it already did for the
  __op__, __rop__ order, but not yet for the __rop__, __op__ order
  when B.__class__ is a subclass of A.__class__.

Also test the refinement added in rev. 2.201 that fixes the problem
reported in SF bug #623669.

Also test a similar provision in abstract.c's binary_op1().