[MERGE] Use utility function to check for control filename rather than assuming it is '.bzr.'

[Ian Clatworthy]

Ian Clatworthy has voted approve.
Status is now: Approved


For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C49FC1A76.4090104%40samba.org%3E
Project: Bazaar