largefiles: missing largefiles should not be committed as removed
Largefiles can easily become missing - for example if it simply isn't available
or the download fail. It might even be convenient to be able to work that way
in some cases.
But commiting missing largefiles as if they had been 'hg remove'd is plain wrong.
Ancestors of 5
4 2 0
Ancestors of 6 and 5
3 4 2 1 0
Ancestors of 5 and 4
4 2 0
Ancestors of 7, stop at 6
6
Ancestors of 7, including revs
7 6 5 3 4 2 1 0
Ancestors of 7, 5 and 3, including revs
7 5 3 6 4 2 1 0
Descendants of 5
7 8
Descendants of 5 and 3
6 7 8
Descendants of 5 and 4
5 7 8