convertbookmark: properly convert stacked bookmarks We ignores pure descendant when looking for revision to convert. This adds support for cases were a linear stack contains multiple bookmark (or un-bookmarked descendants exists). In this case, some changeset are left orphan, but we'll consider the issue as minor for now.

doc generated with sphinx. tutorial exported using sphinxedhg

http://hg.piranha.org.ua/sphinxedhg/