[MERGE/RFC] Remote.readv() breaks up request

[Martin Pool]

Martin Pool has voted approve.
Status is now: Approved
Comment:
Needs a NEWS entry.

This seems reasonable.

It would be nice to add an effort test that we never make larger 
requests, but since it's been tested interactive I think it's reasonable 
as it is.

For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C4908C1EB.3020704%40arbash-meinel.com%3E
Project: Bazaar