[COMMIT] Key aggregate code committed.

Added files:
  key.c
  include/parrot/key.h
  t/op/key.t

Altered files:
  MANIFEST
  Makefile.in
  include/parrot/parrot.h
  core.ops

Implements generic aggregate support in the Sn registers. t/op/key.t has
quick samples of its use. It does have fairly rigorous internal tests,
but the memory allocation is rather primitive. It does do the job, but
as nobody's come up with a memory gc scheme, it doesn't matter yet.

--
Jeff <jgoff@speakeasy.net>

• [COMMIT] Key aggregate code committed. by Jeff G