[mpi3-coll] Missing reduce_local and reduce_scatter_block in create_op text

[Adam T. Moody]

Hi Torsten,
There are a few lists that are missing MPI_REDUCE_LOCAL and 
MPI_REDUCE_SCATTER_BLOCK.

1) Section 5.9.2
List of predefined ops missing MPI_REDUCE_LOCAL, 
MPI_ALLREDUCE_SCATTER_BLOCK, and all non-blocking variants.

2) Description for MPI_OP_CREATE missing MPI_REDUCE_LOCAL, 
MPI_REDUCE_SCATTER_BLOCK, and all non-blocking variants.

I guess we may not need to list the non-blocking variants in this list, 
but we should definitely add REDUCE_LOCAL and REDUCE_SCATTER_BLOCK.
-Adam