templatekw: inline showlist() into showbookmarks()
showlist() is the helper to build _hybrid object from a trivial list. It can't
be applied if each value has more than one items, 'bookmark' and 'current' in
this case.
This change is necessary to fix random failure of "{join(bookmarks, sep)}".
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