[MERGE] Add cross references to bzr help.

[John Arbash Meinel]

John Arbash Meinel has voted +1.
Status is now: Approved
Comment:
At the moment this doesn't seem to be much better than adding a 'See 
also:' line to the help directly.

But I suppose we can update the autogenerated docs so that it actually 
includes HTML links and such.

I'm not sure how to hook into epydoc for this, but we can sort that out 
later, I guess.

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C1176961415.8956.225.camel%40localhost.localdomain%3E