bookmark: do not crash when active bookmark is forward and --date is used
The logic that decides where to update according to the active bookmark
location (when not on ".") was setting the rev to update to before we process
--date. This lead to --date processing aborting because of duplicated
specification.
We reorder the two pieces of code and add a test for this.
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