[MERGE] --no-backup option for bzr upgrade (#118653)

[John Arbash Meinel]

John Arbash Meinel has voted -1.
Status is now: Vetoed
Comment:
Robert voted -1 on the list. There are potential data loss issues from 
--no-backup. And some upgrade code expects to have the backup directory 
so that it can copy the data out of the old repository.

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C1184078494.6288.22.camel%40nemo%3E