[MERGE] Show revnos in `bzr tags`

[Aaron Bentley]

Aaron Bentley has voted abstain.
Status is now: Semi-approved
Comment:
I don't think we should show the revision-ids at all.  If people want 
that, they can use the --show-ids option.  This display should show 
dotted revnos, not just plain revnos.

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C20070908145111.GA8544%40chistera.yi.org%3E