[MERGE] Use repo.supports_rich_root() rather than repo._format.rich_root_data

[Aaron Bentley]

Aaron Bentley has voted +1.
Status is now: Approved


For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C20070301041942.GQ11086%40steerpike.home.puzzling.org%3E