hgweb: sort bookmarks in revlog order of their nodes
Changes, branches and tags are already in revlog order on /summary, /branches
and /tags, let's now make bookmarks be sorted by the same principle. It's more
helpful to show more "recent" bookmarks on top. This will affect /bookmarks
page in all styles, including atom, rss and raw, and also /summary page.
Bookmarks are sorted using a (revision number, bookmark name) tuple.
http://example.com/no/anchor, branches: (None, [])
http://example.com/an/anchor, branches: ('foo', [])
http://example.com/no/anchor/branches, branches: (None, ['foo'])
http://example.com/an/anchor/branches, branches: ('bar', ['foo'])
http://example.com/an/anchor/branches-None, branches: ('foo', [])
http://example.com/, branches: (None, [])
http://example.com/, branches: (None, [])
http://example.com/, branches: ('foo', [])