[Mpi3-rma] Updated MPI-3 RMA proposal 1

[Rajeev Thakur]

We should keep in mind that the rest of the Forum doesn't have RMA
expertise. They won't know whether allflushall is useful or not; they
will look to us to tell them that.

I thought the plan with the two proposals was the following.

Proposal 1: This is what the RMA experts agree is the bare minimum
needed to fix what is considered broken in MPI-2 RMA. 

Proposal 2: These are additional changes that would make MPI RMA even
better. However, if any one logical set of them doesn't make it, it
won't be a deal breaker. 

Since the working group is itself not in agreement whether allflushall
is needed or not, it probably belongs in proposal 2.

Rajeev