ATAG Draft following F2F in McLean VA

Hi,

After a few days of F2F work here's the new internal ATAG draft. The most 
important updates affect:

- most of Part A 
- the checkpoints related to checking and repair

Cheers,
Jan

PS: I have also attached a couple of techniques documents that were not part of 
the group's discussions but which have been partially updated to reflect the 
new structure.