split Process Doc maintenance from AB Advisory Role

This is a suggestion to the AB for consideration in discussions on what 
its role should be.

The AB is an advisory group, but it also controls editing the Process 
document and could block or delay change in the process by refusing to 
move it to AC review.  That puts too much power in a small group that AC 
members cannot join.  We should move that function to an AC taskforce 
that any AC member could join and have the AB focus on its role in 
providing advice.

Proposal: Create a TaskForce in the AC to edit the Process and to govern 
when it goes to the AC for review.

1. Any AC rep can join at any time
2. All AB members are automatically in it, AB chooses chair
3. TaskForce can create multiple proposals for AC review or agree on 
single proposals.
4. All work should be on public process CG list, but may be on an AC 
list (main list or sublist for something sensitive)
5. As now, whatever is proposed moves to the AC for review/approval.
6. AC members or the AB could submit proposals to the TaskForce (so the 
AB could still have a role in developing proposals, just not have a 
choke point on moving a proposal on to the AC)