Updated comment responses for ATAG 2.0 Dec. editor's draft

Hi,

I have updated the comment response grid so that it will be easier for 
us to go over it on the call in 2 weeks.

I have also tried to update things that might have conflicted with the 
changes happening as part of our ongoing checkpoint review.

Please go over this before the call because there is quite a bit there.

Cheers,
Jan