[MERGE][269477] Add documentation about diverged branches and refer to it when pushing fails

[Ian Clatworthy]

Ian Clatworthy has voted approve.
Status is now: Semi-approved
Comment:
Nicely done. Thanks.

For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C4A2C9BED.1020501%40wartburg.edu%3E
Project: Bazaar