test: rename 'list' test to 'stack-data' We are about to add stack data information to 'hg stack'. As we'll re-use the test data creating the 'test-topic-list.t' we need to rename it first to embrace its new semantic.

stack: also dim bases Now that they may have index it seems better to have a stronger marking for bases.

stack: reusing the index number in base when applicable This clarify the branching when it is easy to track back the branching point. This does not takes the evolution graph into account yet.

stack: extra argument validation logic outside of showstack It seems sensible keep the 'showstack' function purely about actually displaying and existing stack.

summary: properly label the topic name in summary This should be labelled 'topic.active' so that color can pick it up properly.

topic: list the branches this topic belong to when verbose Using the verbose listing a bit more, this seems to be useful information.

topic: properly justify the verbose data when listing topic We align all data to the widest topic.