[MERGE] Implement a proper PreviewTree.path_content_summary

Wed Jul 2 18:05:00 BST 2008

John Arbash Meinel has voted approve.
Status is now: Approved
Comment:
As I understand, you are basically allowing path_content_summary to 
inspect nodes that will be created/modified in the transform. As long as 
that is true, this looks correct to me.

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C4863D625.2080800%40aaronbentley.com%3E