[MERGE] Improve "Path(s) are not versioned" error reporting for some commands

[Martin Pool]

Martin Pool has voted tweak.
Status is now: Semi-approved
Comment:
The actual patch looks good, thanks.

It would be nice to have a blackbox test for this in 
blackbox.test_revert.  It may be fairly easy to copy an existing test.

Also it would be nice to mention this in NEWS but we can do that while 
merging.

For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C20090624230503.GA21965%40localdomain%3E
Project: Bazaar