Cosmetics:

Cosmetics:

- Add comment blocks explaining add_operators() and override_slots().
  (This file could use some more explaining, but this is all I had
  breath for today. :)

- Renamed the argument 'base' of add_wrappers() to 'wraps' because
  it's not a base class (which is what the 'base' identifier is used
  for elsewhere).

Small nits:

- Fix add_tp_new_wrapper() to avoid overwriting an existing __new__
  descriptor in tp_defined.

- In add_operators(), check the return value of add_tp_new_wrapper().

Functional change:

- Remove the tp_new functionality from PyBaseObject_Type; this means
  you can no longer instantiate the 'object' type.  It's only useful
  as a base class.

- To make up for the above loss, add tp_new to dynamic types.  This
  has to be done in a hackish way (after override_slots() has been
  called, with an explicit call to add_tp_new_wrapper() at the very
  end) because otherwise I ran into recursive calls of slot_tp_new().
  Sigh.