Make sure we generate the whole commit list before trying to sort it topologically
Make sure we generate the whole commit list before trying to sort it topologically

This was my cherry-pickng merge bug.  But topo-order still shows strange
behaviour with multiple heads, so keep gitk using --merge-order for now.

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git