Capsule-related changes:

Capsule-related changes:
* PyCObject_AsVoidPtr() can now open capsules.  This addresses
  most of the remaining backwards-compatibility concerns about
  the conversion of Python 2.7 from CObjects to capsules.
* CObjects were marked Pending Deprecation.
* Documentation about this pending deprecation was added to
  cobject.h.
* The capsule source files were added to the legacy PC build
  processes.